Fluorine Manager: full Linux port of Mod Organizer 2

Complete native Linux port with FUSE-based virtual filesystem,
Proton/umu-run integration, and Flatpak packaging.

Key features:
- FUSE VFS replacing Windows USVFS (in-process + standalone helper for Flatpak)
- Proton/GE-Proton/umu-run launcher with env var forwarding
- Flatpak support (sandbox-aware VFS, NXM handler, umu-run)
- Wine prefix management UI
- Case-insensitive path resolution for Linux filesystems
- QSettings-safe INI handling (avoids Bethesda INI corruption)
- Portable instance support with auto-generated launcher scripts

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

27 files changed, 3370 insertions, 0 deletions

diff --git a/libs/installer_fomod_csharp/.clang-format b/libs/installer_fomod_csharp/.clang-format
new file mode 100644
index 0000000..6098e1f
--- /dev/null
+++ b/libs/installer_fomod_csharp/.clang-format
@@ -0,0 +1,41 @@
+---
+# We'll use defaults from the LLVM style, but with 4 columns indentation.
+BasedOnStyle: LLVM
+IndentWidth: 2
+---
+Language: Cpp
+DeriveLineEnding: false
+UseCRLF: true
+DerivePointerAlignment: false
+PointerAlignment: Left
+AlignConsecutiveAssignments: true
+AllowShortFunctionsOnASingleLine: Inline
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLambdasOnASingleLine: Empty
+AlwaysBreakTemplateDeclarations: Yes
+AccessModifierOffset: -2
+AlignTrailingComments: true
+SpacesBeforeTrailingComments: 2
+NamespaceIndentation: Inner
+MaxEmptyLinesToKeep: 1
+BreakBeforeBraces: Custom
+BraceWrapping:
+  AfterCaseLabel: false
+  AfterClass: true
+  AfterControlStatement: false
+  AfterEnum: true
+  AfterFunction: true
+  AfterNamespace: true
+  AfterStruct: true
+  AfterUnion: true
+  AfterExternBlock: true
+  BeforeCatch: false
+  BeforeElse: false
+  BeforeLambdaBody: false
+  BeforeWhile: false
+  IndentBraces: false
+  SplitEmptyFunction: false
+  SplitEmptyRecord: false
+  SplitEmptyNamespace: true
+ColumnLimit: 88
+ForEachMacros: ['Q_FOREACH', 'foreach']
diff --git a/libs/installer_fomod_csharp/.git-blame-ignore-revs b/libs/installer_fomod_csharp/.git-blame-ignore-revs
new file mode 100644
index 0000000..a26d6d2
--- /dev/null
+++ b/libs/installer_fomod_csharp/.git-blame-ignore-revs
@@ -0,0 +1 @@
+f45b25a7b347ae5a42ca86ae60a47b177e9caf6e
diff --git a/libs/installer_fomod_csharp/.gitattributes b/libs/installer_fomod_csharp/.gitattributes
new file mode 100644
index 0000000..f869712
--- /dev/null
+++ b/libs/installer_fomod_csharp/.gitattributes
@@ -0,0 +1,7 @@
+# Set the default behavior, in case people don't have core.autocrlf set.
+* text=auto
+
+# Explicitly declare text files you want to always be normalized and converted
+# to native line endings on checkout.
+*.cpp text eol=crlf
+*.h text eol=crlf
diff --git a/libs/installer_fomod_csharp/.github/workflows/build.yml b/libs/installer_fomod_csharp/.github/workflows/build.yml
new file mode 100644
index 0000000..b9d11e3
--- /dev/null
+++ b/libs/installer_fomod_csharp/.github/workflows/build.yml
@@ -0,0 +1,20 @@
+name: Build Installer FOMOD C#
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+env:
+  VCPKG_BINARY_SOURCES: clear;x-azblob,${{ vars.AZ_BLOB_VCPKG_URL }},${{ secrets.AZ_BLOB_SAS }},readwrite
+
+jobs:
+  build:
+    runs-on: windows-2022
+    steps:
+      - name: Build Installer FOMOD C#
+        id: build-installer-fomod-csharp
+        uses: ModOrganizer2/build-with-mob-action@master
+        with:
+          mo2-dependencies: uibase
diff --git a/libs/installer_fomod_csharp/.github/workflows/linting.yml b/libs/installer_fomod_csharp/.github/workflows/linting.yml
new file mode 100644
index 0000000..80d5fd4
--- /dev/null
+++ b/libs/installer_fomod_csharp/.github/workflows/linting.yml
@@ -0,0 +1,16 @@
+name: Lint Installer FOMOD C# Plugin
+
+on:
+  push:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Check format
+        uses: ModOrganizer2/check-formatting-action@master
+        with:
+          check-path: "."
diff --git a/libs/installer_fomod_csharp/.gitignore b/libs/installer_fomod_csharp/.gitignore
new file mode 100644
index 0000000..58b3448
--- /dev/null
+++ b/libs/installer_fomod_csharp/.gitignore
@@ -0,0 +1 @@
+vsbuild
diff --git a/libs/installer_fomod_csharp/.pre-commit-config.yaml b/libs/installer_fomod_csharp/.pre-commit-config.yaml
new file mode 100644
index 0000000..3103a1f
--- /dev/null
+++ b/libs/installer_fomod_csharp/.pre-commit-config.yaml
@@ -0,0 +1,20 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-merge-conflict
+      - id: check-case-conflict
+  - repo: https://github.com/pre-commit/mirrors-clang-format
+    rev: v19.1.5
+    hooks:
+    - id: clang-format
+      'types_or': [c++, c]
+
+ci:
+  autofix_commit_msg: "[pre-commit.ci] Auto fixes from pre-commit.com hooks."
+  autofix_prs: true
+  autoupdate_commit_msg: "[pre-commit.ci] Pre-commit autoupdate."
+  autoupdate_schedule: quarterly
+  submodules: false
diff --git a/libs/installer_fomod_csharp/CMakeLists.txt b/libs/installer_fomod_csharp/CMakeLists.txt
new file mode 100644
index 0000000..3170ab3
--- /dev/null
+++ b/libs/installer_fomod_csharp/CMakeLists.txt
@@ -0,0 +1,5 @@
+cmake_minimum_required(VERSION 3.16)
+
+project(installer_fomod_csharp)
+
+add_subdirectory(src)
diff --git a/libs/installer_fomod_csharp/CMakePresets.json b/libs/installer_fomod_csharp/CMakePresets.json
new file mode 100644
index 0000000..5a63c77
--- /dev/null
+++ b/libs/installer_fomod_csharp/CMakePresets.json
@@ -0,0 +1,67 @@
+{
+  "configurePresets": [
+    {
+      "errors": {
+        "deprecated": true
+      },
+      "hidden": true,
+      "name": "cmake-dev",
+      "warnings": {
+        "deprecated": true,
+        "dev": true
+      }
+    },
+    {
+      "cacheVariables": {
+        "VCPKG_MANIFEST_NO_DEFAULT_FEATURES": {
+          "type": "BOOL",
+          "value": "ON"
+        }
+      },
+      "toolchainFile": "$env{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake",
+      "hidden": true,
+      "name": "vcpkg"
+    },
+    {
+      "hidden": true,
+      "inherits": ["vcpkg"],
+      "name": "vcpkg-dev"
+    },
+    {
+      "binaryDir": "${sourceDir}/vsbuild",
+      "architecture": {
+        "strategy": "set",
+        "value": "x64"
+      },
+      "cacheVariables": {
+        "CMAKE_CXX_FLAGS": "/EHsc /MP /W4",
+        "VCPKG_TARGET_TRIPLET": {
+          "type": "STRING",
+          "value": "x64-windows-static-md"
+        }
+      },
+      "generator": "Visual Studio 17 2022",
+      "inherits": ["cmake-dev", "vcpkg-dev"],
+      "name": "vs2022-windows",
+      "toolset": "v143"
+    },
+    {
+      "cacheVariables": {
+        "VCPKG_MANIFEST_FEATURES": {
+          "type": "STRING",
+          "value": "standalone"
+        }
+      },
+      "inherits": "vs2022-windows",
+      "name": "vs2022-windows-standalone"
+    }
+  ],
+  "buildPresets": [
+    {
+      "name": "vs2022-windows",
+      "resolvePackageReferences": "on",
+      "configurePreset": "vs2022-windows"
+    }
+  ],
+  "version": 4
+}
diff --git a/libs/installer_fomod_csharp/LICENSE b/libs/installer_fomod_csharp/LICENSE
new file mode 100644
index 0000000..f288702
--- /dev/null
+++ b/libs/installer_fomod_csharp/LICENSE
@@ -0,0 +1,674 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
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+software and other kinds of works.
+
+  The licenses for most software and other practical works are designed
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+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors.  You can apply it to
+your programs, too.
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+  A patent license is "discriminatory" if it does not include within
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+
+  Nothing in this License shall be construed as excluding or limiting
+any implied license or other defenses to infringement that may
+otherwise be available to you under applicable patent law.
+
+  12. No Surrender of Others' Freedom.
+
+  If conditions are imposed on you (whether by court order, agreement or
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+to collect a royalty for further conveying from those to whom you convey
+the Program, the only way you could satisfy both those terms and this
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+
+  13. Use with the GNU Affero General Public License.
+
+  Notwithstanding any other provision of this License, you have
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+  14. Revised Versions of this License.
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+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+  Each version is given a distinguishing version number.  If the
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+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
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+
+  If the Program specifies that a proxy can decide which future
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+  Later license versions may give you additional or different
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+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
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+  16. Limitation of Liability.
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+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
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+SUCH DAMAGES.
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+  17. Interpretation of Sections 15 and 16.
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+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
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+  If the program does terminal interaction, make it output a short
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+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.
diff --git a/libs/installer_fomod_csharp/README.md b/libs/installer_fomod_csharp/README.md
new file mode 100644
index 0000000..6b4e4d1
--- /dev/null
+++ b/libs/installer_fomod_csharp/README.md
@@ -0,0 +1,20 @@
+# [MO2](https://github.com/ModOrganizer2/modorganizer) plugin for FOMOD installers using C# scripts
+
+This is simple installer plugin for Mod Organizer 2 to handle FOMOD installers containing C# script.
+
+Without this plugin, Mod Organizer 2 will use NCC to install such plugins, but NCC has a few limitations when
+used within MO2:
+
+- Mod detection will not work, so the installer will not be able to check for active mods or even existing files.
+- Modifying settings (`FalloutNV.ini`, etc.) does not work properly with the NCC installer (it may work if you
+    do not use per-profile settings, but that is not recommended).
+
+This installer is better integrated with Mod Organizer 2 and should handle any kind of FOMOD installer containing
+a C# script. Feel free to [open an issue](https://github.com/ModOrganizer2/modorganizer/issues/new?assignees=&labels=issue+report&template=issue-report.md)
+if you find a bug.
+
+The installer will never modify settings silently. If during installation, the script tries to modify settings,
+they will be stored in memory and presented to you at the end of the installation. You will then be able to either
+apply the settings, save them inside the mod folder or discard them.
+
+**Warning:** This plugin currently only works with Mod Organizer 2 development build 2.3.0 alpha 10!
diff --git a/libs/installer_fomod_csharp/src/CMakeLists.txt b/libs/installer_fomod_csharp/src/CMakeLists.txt
new file mode 100644
index 0000000..09b3015
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/CMakeLists.txt
@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.16)
+
+find_package(mo2-cmake CONFIG REQUIRED)
+find_package(mo2-uibase CONFIG REQUIRED)
+
+add_library(installer_fomod_csharp SHARED)
+mo2_configure_plugin(installer_fomod_csharp WARNINGS OFF CLI ON)
+target_link_libraries(installer_fomod_csharp PRIVATE mo2::uibase)
+mo2_install_plugin(installer_fomod_csharp)
+
+set_target_properties(installer_fomod_csharp PROPERTIES CXX_STANDARD 20)
diff --git a/libs/installer_fomod_csharp/src/base_script.cpp b/libs/installer_fomod_csharp/src/base_script.cpp
new file mode 100644
index 0000000..e3aa4a7
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/base_script.cpp
@@ -0,0 +1,685 @@
+/*
+Copyright (C) 2020 Holt59. All rights reserved.
+
+Mod Organizer is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Mod Organizer is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Mod Organizer.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "base_script.h"
+
+#include <filesystem>
+#include <map>
+
+#include <QCheckBox>
+#include <QDialogButtonBox>
+#include <QInputDialog>
+#include <QLabel>
+#include <QMessageBox>
+#include <QPushButton>
+#include <QRadioButton>
+#include <QSettings>
+#include <QVBoxLayout>
+#include <QVersionNumber>
+
+#include <uibase/game_features/igamefeatures.h>
+#include <uibase/game_features/scriptextender.h>
+#include <uibase/iinstallationmanager.h>
+#include <uibase/imoinfo.h>
+#include <uibase/iplugingame.h>
+#include <uibase/ipluginlist.h>
+#include <uibase/log.h>
+
+#include "csharp_interface.h"
+#include "csharp_utils.h"
+#include "installer_fomod_postdialog.h"
+#include "psettings.h"
+
+using namespace MOBase;
+
+// clang-format off
+
+namespace CSharp {
+
+  // Pointer to object:
+  static MOBase::IOrganizer* g_Organizer = nullptr;
+
+  // Per-install globals:
+  struct Globals {
+    IInstallationManager* InstallManager;
+    QWidget* ParentWidget;
+    std::shared_ptr<const IFileTree> SourceTree;
+    std::shared_ptr<IFileTree> DestinationTree;
+
+    // Map from path in destination entry to the original entry:
+    std::map<std::shared_ptr<const FileTreeEntry>,
+      std::shared_ptr<const FileTreeEntry>> InstalledEntries;
+
+    // Map extracted entries (in the original tree) to (temporary) paths:
+    std::map<std::shared_ptr<const FileTreeEntry>, QString> ExtractedEntries;
+
+    // Map creted entries (in the destination tree) to (temporary) paths:
+    std::map<std::shared_ptr<const FileTreeEntry>, QString> CreatedEntries;
+
+    // List of modified settings values:
+    std::map<QString, PSettings> Settings;
+
+    Globals() { }
+    Globals(
+      IPlugin const* plugin, MOBase::IInstallationManager* manager, QWidget* parentWidget,
+      std::shared_ptr<MOBase::IFileTree> tree, std::map<std::shared_ptr<const FileTreeEntry>, QString> entries) :
+      m_Plugin(plugin), InstallManager(manager), ParentWidget(parentWidget), SourceTree(tree), DestinationTree(tree->createOrphanTree()), ExtractedEntries(std::move(entries)) {
+
+    }
+
+    Globals(Globals const&) = delete;
+    Globals(Globals&&) = default;
+
+    Globals& operator=(Globals const&) = delete;
+    Globals& operator=(Globals&&) = default;
+
+  private:
+    IPlugin const* m_Plugin;
+  };
+  static Globals g;
+
+
+
+  void init(MOBase::IOrganizer* moInfo) {
+
+    // Do this only once:
+    if (g_Organizer == nullptr) {
+      Application::EnableVisualStyles();
+      Application::SetCompatibleTextRenderingDefault(false);
+    }
+
+    g_Organizer = moInfo;
+  }
+
+  void beforeInstall(IPlugin const* plugin, MOBase::IInstallationManager* manager, QWidget* parentWidget,
+    std::shared_ptr<MOBase::IFileTree> tree, std::map<std::shared_ptr<const FileTreeEntry>, QString> entries) {
+    g = { plugin, manager, parentWidget, tree, std::move(entries) };
+  }
+
+  IPluginInstaller::EInstallResult postInstall(std::shared_ptr<MOBase::IFileTree>& tree) {
+
+    if (!g.Settings.empty()) {
+
+      InstallerFomodPostDialog* dialog = new InstallerFomodPostDialog(g.ParentWidget);
+
+      dialog->setIniSettings(g.Settings);
+
+      // Installation cancelled:
+      if (dialog->exec() == QDialog::Rejected) {
+        return IPluginInstaller::EInstallResult::RESULT_CANCELED;
+      }
+
+      switch (dialog->result()) {
+
+        // Discard, nothing do to:
+      case InstallerFomodPostDialog::Result::DISCARD: break;
+
+        // Apply, must fetch the profile INI settings and apply the settings:
+      case InstallerFomodPostDialog::Result::APPLY: {
+        for (auto& p : g.Settings) {
+          QDir path(g_Organizer->profilePath());
+          if (!g_Organizer->profile()->localSettingsEnabled()) {
+            path = QDir(g_Organizer->managedGame()->documentsDirectory());
+          }
+
+          QSettings settings(path.filePath(p.first), QSettings::IniFormat);
+
+          if (settings.status() != QSettings::NoError) {
+            return IPluginInstaller::EInstallResult::RESULT_FAILED;
+          }
+
+          p.second.update(settings);
+        }
+      } break;
+
+                                                  // Move, must create the INI files and apply the settings:
+      case InstallerFomodPostDialog::Result::MOVE: {
+        for (auto& p : g.Settings) {
+          auto e = g.DestinationTree->addFile("INI Tweaks/" + p.first, false);
+          if (e == nullptr) {
+            return IPluginInstaller::EInstallResult::RESULT_FAILED;
+          }
+          QString path = g.InstallManager->createFile(e);
+          if (path.isEmpty()) {
+            return IPluginInstaller::EInstallResult::RESULT_FAILED;
+          }
+          QSettings settings(path, QSettings::IniFormat);
+          if (settings.status() != QSettings::NoError) {
+            return IPluginInstaller::EInstallResult::RESULT_FAILED;
+          }
+          p.second.update(settings);
+        }
+      } break;
+      }
+
+    }
+
+    tree = g.DestinationTree;
+
+    // Clear up:
+    g = Globals();
+
+
+    return IPluginInstaller::EInstallResult::RESULT_SUCCESS;
+  }
+
+}
+
+namespace CSharp {
+
+  using namespace System::IO;
+
+  bool isFomodEntry(std::shared_ptr<const FileTreeEntry> entry) {
+    return entry->pathFrom(g.SourceTree).compare("fomod", Qt::CaseInsensitive) == 0;
+  }
+
+  bool BaseScriptImpl::PerformBasicInstall() {
+    for (auto e : *g.SourceTree) {
+      if (!isFomodEntry(e)) {
+        auto ce = g.DestinationTree->copy(e, "", IFileTree::InsertPolicy::MERGE);
+        g.InstalledEntries[ce] = e;
+      }
+    }
+    return true;
+  }
+
+  bool BaseScriptImpl::InstallFileFromMod(String^ p_strFrom, String^ p_strTo) {
+    auto sourceEntry = g.SourceTree->find(to_qstring(p_strFrom));
+
+    if (!sourceEntry) {
+      log::warn("File '{}' not found in the archive.", to_wstring(p_strFrom));
+      return false;
+    }
+
+    if (auto ce = g.DestinationTree->copy(sourceEntry, to_qstring(p_strTo)); ce != nullptr) {
+      g.InstalledEntries[ce] = sourceEntry;
+      return true;
+    }
+
+    return false;
+  }
+
+  array<String^>^ BaseScriptImpl::GetModFileList() {
+    // Cannot directly fill a, e.g., List<String^>^ because I cannot capture it:
+    std::vector<QString> paths;
+    g.SourceTree->walk([&](QString const& path, std::shared_ptr<const FileTreeEntry> entry) {
+      // Discard fomod folder:
+      if (isFomodEntry(entry)) {
+        return IFileTree::WalkReturn::SKIP;
+      }
+      if (entry->isFile()) {
+        paths.push_back(path + entry->name());
+      }
+      return IFileTree::WalkReturn::CONTINUE;
+      }, "/");
+
+    // Convert to C#:
+    const auto size = static_cast<int>(paths.size());
+    array<String^>^ result = gcnew array<String^>(size);
+    for (int i = 0; i < size; ++i) {
+      result[i] = from_string(paths[i].toStdWString());
+    }
+
+    return result;
+  }
+
+
+  /**
+   * @brief Extract the given entry.
+   *
+   * If the entry has already been extracted, the existing paths is returned.
+   *
+   * @param entry The entry to extract.
+   *
+   * @return path to the temporary file corresponding to the entry.
+   */
+  QString extractFile(std::shared_ptr<const FileTreeEntry> entry) {
+
+    QString qPath;
+    if (auto it = g.ExtractedEntries.find(entry); it != g.ExtractedEntries.end()) {
+      qPath = it->second;
+    }
+    else {
+      qPath = g.InstallManager->extractFile(entry, true);
+
+      if (qPath.isEmpty()) {
+        return QString();
+      }
+
+      g.ExtractedEntries[entry] = qPath;
+    }
+
+    return qPath;
+  }
+
+  array<Byte>^ BaseScriptImpl::GetFileFromMod(String^ p_strFile) {
+    auto entry = g.SourceTree->find(to_qstring(p_strFile));
+
+    if (!entry) {
+      return gcnew array<Byte>(0);
+    }
+
+    QString qPath = extractFile(entry);
+    if (qPath.isEmpty()) {
+      return gcnew array<Byte>(0);
+    }
+
+    String^ path = from_string(qPath.toStdWString());
+    return File::ReadAllBytes(path);
+  }
+
+  QStringList getDataFiles(QString folder, QString pattern, bool allFolders) {
+    QStringList files = g_Organizer->findFiles(folder, [pattern](QString const& filepath) {
+      return QDir::match(pattern, QFileInfo(filepath).fileName());
+      });
+    if (allFolders) {
+      QStringList directories = g_Organizer->listDirectories(folder);
+      for (QString directory : directories) {
+        // MO2 does not like path with . or / (I think), so creating the path manually:
+        files.append(getDataFiles((folder.isEmpty() ? "" : folder + QDir::separator()) + directory, pattern, allFolders));
+      }
+    }
+    return files;
+  }
+
+  array<String^>^ BaseScriptImpl::GetExistingDataFileList(String^ p_strPath, String^ p_strPattern, bool p_booAllFolders) {
+    QStringList files = getDataFiles(to_qstring(p_strPath), to_qstring(p_strPattern), p_booAllFolders);
+    array<String^>^ result = gcnew array<String^>(files.size());
+
+    QDir modsDir(g_Organizer->modsPath());
+    for (int i = 0; i < files.size(); ++i) {
+      // We need to trim the path to the actual folder containing the mod (did not find a better way):
+      QString rpath = modsDir.relativeFilePath(files[i]).replace("/", QDir::separator());
+      result[i] = from_string(rpath.mid(rpath.indexOf(QDir::separator()) + 1).toStdWString());
+    }
+    return result;
+  }
+
+  /**
+   * @brief Find the data-file path corresponding to the given path.
+   *
+   * This methods first lookup the file in the destination tree of the mod (for files
+   * that have been extracted / created by the mod), and if it does not find it there
+   * lookup files from other mods.
+   *
+   * @param p_strPath Path to the file to lookup, relative to the data folder.
+   *
+   * @return a path to an actual corresponding file, or a null pointer if the
+   *   file was not found.
+   */
+  String^ getDataFilePath(String^ p_strPath) {
+
+    // Check if the file is in the output tree:
+    QString qPath = to_qstring(p_strPath);
+    if (auto e = g.DestinationTree->find(qPath); e != nullptr) {
+
+      // Check if it's a created entry:
+      if (auto it = g.CreatedEntries.find(e); it != g.CreatedEntries.end()) {
+        return from_string(g.CreatedEntries[e]);
+      }
+
+      // Find the source entry - We need to check for parent:
+      std::shared_ptr<const FileTreeEntry> originalEntry;
+      if (auto it = g.InstalledEntries.find(e); it != g.InstalledEntries.end()) {
+        originalEntry = it->second;
+      }
+      else {
+        std::shared_ptr<const IFileTree> tree = e->parent();
+        decltype(tree) oTree = nullptr;
+        while (oTree == nullptr && tree != nullptr) {
+          auto it = g.InstalledEntries.find(tree);
+          if (it != g.InstalledEntries.end()) {
+            oTree = it->second->astree();
+          }
+          else {
+            tree = tree->parent();
+          }
+        }
+        originalEntry = oTree->find(e->pathFrom(tree));
+      }
+      QString path = extractFile(originalEntry);
+      if (path.isEmpty()) {
+        return nullptr;
+      }
+      return from_string(path);
+    }
+
+    // Convert to path and normalize separator:
+    auto path = std::filesystem::path(qPath.toStdWString()).make_preferred();
+    QStringList paths = g_Organizer->findFiles(ToQString(path.parent_path().native()), [name = ToQString(path.filename())](QString const& filepath) {
+      return QFileInfo(filepath).fileName().compare(name, Qt::CaseInsensitive) == 0;
+      });
+
+    if (paths.isEmpty()) {
+      return nullptr;
+    }
+
+    return from_string(paths[0]);
+  }
+
+  bool BaseScriptImpl::DataFileExists(String^ p_strPath) {
+    return getDataFilePath(p_strPath) != nullptr;
+  }
+
+  array<Byte>^ BaseScriptImpl::GetExistingDataFile(String^ p_strPath) {
+
+    // Convert to path and normalize separator:
+    String^ datapath = getDataFilePath(p_strPath);
+
+    if (datapath == nullptr) {
+      return nullptr;
+    }
+
+    // Read the first file (should be only one):
+    return File::ReadAllBytes(datapath);
+  }
+
+  bool BaseScriptImpl::GenerateDataFile(String^ p_strPath, array<Byte>^ p_bteData) {
+
+    // Check if we already have created an entry for this:
+    QString qPath = to_qstring(p_strPath);
+    auto entry = g.DestinationTree->find(qPath);
+
+    QString qAbsPath;
+    // If the entry is in the list of created files (note: if the entry does not exist,
+    // find return a nullptr, which is never in g.CreatedEntries).
+    if (auto it = g.CreatedEntries.find(entry); it != g.CreatedEntries.end()) {
+      qAbsPath = g.CreatedEntries.at(entry);
+    }
+    // Otherwize: Create the entry and the temporary file:
+    else {
+      entry = g.DestinationTree->addFile(qPath, true);
+      qAbsPath = g.InstallManager->createFile(entry);
+      if (qAbsPath.isEmpty()) {
+        // Remove the entry from the tree:
+        entry->detach();
+        return false;
+      }
+
+      // Store the created entry:
+      g.CreatedEntries[entry] = qAbsPath;
+    }
+
+    String^ absPath = from_string(qAbsPath);
+    File::WriteAllBytes(absPath, p_bteData);
+    return true;
+  }
+
+  // UI methods:
+
+  DialogResult BaseScriptImpl::ExtendedMessageBox(String^ p_strMessage, String^ p_strTitle, String^ p_strDetails, MessageBoxButtons p_mbbButtons, MessageBoxIcon p_mdiIcon) {
+    QMessageBox messageBox(g.ParentWidget);
+    if (!String::IsNullOrEmpty(p_strTitle)) {
+      messageBox.setWindowTitle(to_qstring(p_strTitle));
+    }
+    messageBox.setText(to_qstring(p_strMessage));
+
+    if (!String::IsNullOrEmpty(p_strDetails)) {
+      messageBox.setDetailedText(to_qstring(p_strDetails));
+    }
+
+    // For whatever reason MessageBoxIcon has duplicated entries...
+    switch (p_mdiIcon) {
+    case MessageBoxIcon::Error:
+      // case MessageBoxIcon::Stop:
+      messageBox.setIcon(QMessageBox::Icon::Critical);
+      break;
+    case MessageBoxIcon::Asterisk:
+      // case MessageBoxIcon::Information:
+      messageBox.setIcon(QMessageBox::Icon::Information);
+      break;
+    case MessageBoxIcon::Question:
+      messageBox.setIcon(QMessageBox::Icon::Question);
+      break;
+    case MessageBoxIcon::Exclamation:
+      // case MessageBoxIcon::Hand:
+      // case MessageBoxIcon::Warning:
+      // case MessageBoxIcon::None:
+      messageBox.setIcon(QMessageBox::Icon::Warning);
+    case MessageBoxIcon::None:
+      messageBox.setIcon(QMessageBox::Icon::NoIcon);
+      break;
+    }
+
+    QMessageBox::StandardButtons buttons;
+
+    switch (p_mbbButtons) {
+    case MessageBoxButtons::AbortRetryIgnore:
+      buttons = QMessageBox::StandardButton::Abort | QMessageBox::StandardButton::Retry | QMessageBox::StandardButton::Ignore;
+      break;
+    case MessageBoxButtons::OK:
+      buttons = QMessageBox::StandardButton::Ok;
+      break;
+    case MessageBoxButtons::OKCancel:
+      buttons = QMessageBox::StandardButton::Ok | QMessageBox::Cancel;
+      break;
+    case MessageBoxButtons::RetryCancel:
+      buttons = QMessageBox::StandardButton::Cancel | QMessageBox::StandardButton::Retry;
+      break;
+    case MessageBoxButtons::YesNoCancel:
+      buttons = QMessageBox::StandardButton::Yes | QMessageBox::No | QMessageBox::Cancel;
+      break;
+    case MessageBoxButtons::YesNo:
+      buttons = QMessageBox::StandardButton::Yes | QMessageBox::No;
+      break;
+    }
+
+    messageBox.setStandardButtons(buttons);
+
+    // Only some case are possible here:
+    switch (messageBox.exec()) {
+    case QMessageBox::Button::Abort:
+      return DialogResult::Abort;
+    case QMessageBox::Button::Cancel:
+      return DialogResult::Cancel;
+    case QMessageBox::Button::Ignore:
+      return DialogResult::Ignore;
+    case QMessageBox::Button::No:
+      return DialogResult::No;
+    case QMessageBox::Button::Ok:
+      return DialogResult::OK;
+    case QMessageBox::Button::Retry:
+      return DialogResult::Retry;
+    case QMessageBox::Button::Yes:
+      return DialogResult::Yes;
+    }
+
+    return DialogResult::None;
+  }
+
+
+  array<int>^ BaseScriptImpl::Select(array<SelectOption^>^ p_sopOptions, String^ p_strTitle, bool p_booSelectMany) {
+    using namespace System::Collections::Generic;
+
+    QDialog* inputDialog = new QDialog();
+    QVBoxLayout* layout = new QVBoxLayout(inputDialog);
+    inputDialog->setWindowTitle(to_qstring(p_strTitle));
+    inputDialog->setLayout(layout);
+
+    layout->setSizeConstraint(QLayout::SetFixedSize);
+
+    if (p_booSelectMany) {
+      layout->addWidget(new QLabel(QObject::tr("Choose any:"), inputDialog));
+    }
+    else {
+      layout->addWidget(new QLabel(QObject::tr("Choose one:"), inputDialog));
+    }
+
+    QList<QAbstractButton*> items;
+    for each (SelectOption ^ opt in p_sopOptions) {
+      QAbstractButton* btn;
+      if (p_booSelectMany) {
+        btn = new QCheckBox(to_qstring(opt->Item), inputDialog);
+      }
+      else {
+        btn = new QRadioButton(to_qstring(opt->Item), inputDialog);
+      }
+
+      if (!String::IsNullOrEmpty(opt->Desc)) {
+        btn->setToolTip(to_qstring(opt->Desc));
+      }
+
+      layout->addWidget(btn);
+      items.append(btn);
+    }
+
+    if (!p_booSelectMany && items.size() > 0) {
+      items[0]->setChecked(true);
+    }
+
+    QDialogButtonBox* buttonBox = new QDialogButtonBox(
+      QDialogButtonBox::Cancel | QDialogButtonBox::Ok, inputDialog);
+    layout->addWidget(buttonBox);
+
+    // Using old signal/slot syntax since the new one does not work here (probably
+    // due to the C++/CLR nature):
+    QObject::connect(buttonBox, SIGNAL(accepted()), inputDialog, SLOT(accept()));
+    QObject::connect(buttonBox, SIGNAL(rejected()), inputDialog, SLOT(reject()));
+
+    inputDialog->setModal(true);
+    if (inputDialog->exec() != QDialog::Accepted) {
+      return gcnew array<int>(0);
+    }
+
+    List<int>^ selected = gcnew List<int>(items.size());
+    for (int i = 0; i < items.size(); ++i) {
+      if (items[i]->isChecked()) {
+        selected->Add(i);
+      }
+    }
+
+    return selected->ToArray();
+  }
+
+  // Versioning / INIs:
+
+  // Convert to Version^ from a MO2 version:
+  inline System::Version^ make_version(VersionInfo version) {
+    auto qversion = version.asQVersionNumber();
+    return gcnew System::Version(qversion.majorVersion(), qversion.minorVersion(), qversion.microVersion());
+
+  }
+
+  System::Version^ BaseScriptImpl::GetModManagerVersion() {
+    const auto version = g_Organizer->version();
+    return gcnew System::Version(version.major(), version.minor(), version.patch());
+  }
+
+  System::Version^ BaseScriptImpl::GetGameVersion() {
+    return make_version(g_Organizer->managedGame()->gameVersion());
+  }
+
+  System::Version^ BaseScriptImpl::GetScriptExtenderVersion() {
+    auto scriptExtender = g_Organizer->gameFeatures()->gameFeature<ScriptExtender>();
+
+    if (!scriptExtender || !scriptExtender->isInstalled()) {
+      return nullptr;
+    }
+
+    return gcnew System::Version(msclr::interop::marshal_as<String^>(scriptExtender->getExtenderVersion().toStdString()));
+  }
+
+  bool BaseScriptImpl::ScriptExtenderPresent() {
+    auto scriptExtender = g_Organizer->gameFeatures()->gameFeature<ScriptExtender>();
+    return scriptExtender && scriptExtender->isInstalled();
+  }
+
+  // Plugins:
+  array<String^>^ BaseScriptImpl::GetAllPlugins() {
+    QStringList names = g_Organizer->pluginList()->pluginNames();
+    array<String^>^ result = gcnew array<String^>(names.size());
+    for (int i = 0; i < names.size(); ++i) {
+      result[i] = from_string(names[i].toStdString());
+    }
+    return result;
+  }
+
+  array<String^>^ BaseScriptImpl::GetActivePlugins() {
+    auto pluginList = g_Organizer->pluginList();
+    QStringList names = pluginList->pluginNames();
+    QStringList activeNames;
+    for (auto& name : names) {
+      if (pluginList->state(name) == IPluginList::STATE_ACTIVE) {
+        activeNames.append(name);
+      }
+    }
+    array<String^>^ result = gcnew array<String^>(activeNames.size());
+    for (int i = 0; i < activeNames.size(); ++i) {
+      result[i] = from_string(activeNames[i].toStdString());
+    }
+    return result;
+  }
+
+  // INIs:
+  String^ BaseScriptImpl::GetIniString(String^ settingsFileName, String^ section, String^ key) {
+
+    // Check if we have already set this within this installation:
+    auto fIt = g.Settings.find(to_qstring(settingsFileName));
+    if (fIt != g.Settings.end()) {
+      QString value = fIt->second.value(to_qstring(section), to_qstring(key));
+      if (!value.isEmpty()) {
+        return from_string(value);
+      }
+    }
+
+    // Otherwize, look-up the file:
+    QDir path(g_Organizer->profilePath());
+    if (!g_Organizer->profile()->localSettingsEnabled()) {
+      path = QDir(g_Organizer->managedGame()->documentsDirectory());
+    }
+
+    QSettings settings(path.filePath(to_qstring(settingsFileName)), QSettings::IniFormat);
+
+    if (settings.status() != QSettings::NoError) {
+      return nullptr;
+    }
+
+    QString name = to_qstring(section + "/" + key);
+    if (section->Equals("General", System::StringComparison::CurrentCultureIgnoreCase)) {
+      name = to_qstring(key);
+    }
+
+    QVariant value = settings.value(name);
+    if (!value.isValid()) {
+      return nullptr;
+    }
+
+    return from_string(value.toString().toStdString());
+  }
+
+  int BaseScriptImpl::GetIniInt(String^ settingsFileName, String^ section, String^ key) {
+    return Convert::ToInt32(GetIniString(settingsFileName, section, key));
+  }
+
+  bool BaseScriptImpl::EditIni(String^ p_strSettingsFileName, String^ p_strSection, String^ p_strKey, String^ p_strValue) {
+    // Check that the file is supported:
+    bool iniFound = false;
+    for (auto ini : g_Organizer->managedGame()->iniFiles()) {
+      if (ini.compare(to_qstring(p_strSettingsFileName), Qt::CaseInsensitive) == 0) {
+        iniFound = true;
+      }
+    }
+
+    if (!iniFound) {
+      return false;
+    }
+
+    g.Settings[to_qstring(p_strSettingsFileName)].setValue(to_qstring(p_strSection), to_qstring(p_strKey), to_qstring(p_strValue));
+    return true;
+  }
+
+}
diff --git a/libs/installer_fomod_csharp/src/base_script.h b/libs/installer_fomod_csharp/src/base_script.h
new file mode 100644
index 0000000..abfa152
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/base_script.h
@@ -0,0 +1,552 @@
+/*
+Copyright (C) 2020 Holt59. All rights reserved.
+
+Mod Organizer is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Mod Organizer is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Mod Organizer.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// clang-format off
+
+#ifndef BASE_SCRIPT_H
+#define BASE_SCRIPT_H
+
+#using <System.dll>
+#using <System.Drawing.dll>
+#using <System.Windows.Forms.dll>
+
+#include <uibase/iplugininstaller.h>
+
+/**
+ * Note: The specification of BaseScript where taken from the Nexus-Mods installer_fomod extension
+ * for Vortex: https://github.com/Nexus-Mods/fomod-installer
+ */
+namespace CSharp {
+
+  using namespace System;
+  using namespace System::Drawing;
+  using namespace System::Windows::Forms;
+
+  /// <summary>
+  /// Describes the options to display in a select form.
+  /// </summary>
+  public ref struct SelectOption {
+  public:
+    /// <summary>
+    /// The name of the selection item.
+    /// </summary>
+    String^ Item;
+
+    /// <summary>
+    /// The path to the preview image of the item.
+    /// </summary>
+    String^ Preview;
+
+    /// <summary>
+    /// The description of the selection item.
+    /// </summary>
+    String^ Desc;
+
+    /// <summary>
+    /// A simple constructor that initializes the struct with the given values.
+    /// </summary>
+    /// <param name="item">The name of the selection item.</param>
+    /// <param name="preview">The path to the preview image of the item.</param>
+    /// <param name="desc">The description of the selection item.</param>
+    SelectOption(String^ item, String^ preview, String^ desc) {
+      Item = item;
+      Preview = preview;
+      Desc = desc;
+    }
+  };
+
+  /// <summary>
+  /// The base class for C# scripts.
+  /// </summary>
+  public ref class BaseScriptImpl {
+  public:
+
+    static String^ LastError;
+
+    /// <summary>
+    /// Returns the last error that occurred.
+    /// </summary>
+    /// <returns>The last error that occurred.</returns>
+    static String^ GetLastError() {
+        return LastError;
+    }
+
+    /// <summary>
+    /// Performs a basic install of the mod.
+    /// </summary>
+    /// <remarks>
+    /// A basic install installs all of the file in the mod to the Data directory
+    /// or activates all esp and esm files.
+    /// </remarks>
+    /// <returns><c>true</c> if the installation succeed;
+    /// <c>false</c> otherwise.</returns>
+    static bool PerformBasicInstall();
+
+    /// <summary>
+    /// Installs the specified file from the mod to the specified location on the file system.
+    /// </summary>
+    /// <remarks>
+    /// This is the legacy form of <see cref="InstallFileFromMod(string, string)"/>. It now just calls
+    /// <see cref="InstallFileFromMod(string, string)"/>.
+    /// </remarks>
+    /// <param name="p_strFrom">The path of the file in the mod to install.</param>
+    /// <param name="p_strTo">The path on the file system where the file is to be created.</param>
+    /// <returns><c>true</c> if the file was written; <c>false</c> otherwise.</returns>
+    /// <seealso cref="InstallFileFromMod(string, string)"/>
+    static bool CopyDataFile(String^ p_strFrom, String^ p_strTo) {
+      return InstallFileFromMod(p_strFrom, p_strTo);
+    }
+
+    /// <summary>
+    /// Installs the specified file from the mod to the specified location on the file system.
+    /// </summary>
+    /// <param name="p_strFrom">The path of the file in the mod to install.</param>
+    /// <param name="p_strTo">The path on the file system where the file is to be created.</param>
+    /// <returns><c>true</c> if the file was written; <c>false</c> otherwise.</returns>
+    static bool InstallFileFromMod(String^ p_strFrom, String^ p_strTo);
+
+    /// <summary>
+    /// Installs the speified file from the mod to the file system.
+    /// </summary>
+    /// <param name="p_strFile">The path of the file to install.</param>
+    /// <returns><c>true</c> if the file was written; <c>false</c> otherwise.</returns>
+    static bool InstallFileFromMod(String^ p_strFile) {
+      return InstallFileFromMod(p_strFile, p_strFile);
+    }
+
+    /// <summary>
+    /// Installs the specified file from the mod to the specified location on the file system.
+    /// </summary>
+    /// <param name="p_strFrom">The path of the file in the mod to install.</param>
+    /// <param name="p_strTo">The path on the file system where the file is to be created.</param>
+    /// <returns><c>true</c> if the file was written; <c>false</c> otherwise.</returns>
+    static bool InstallFileFromFomod(String^ p_strFrom, String^ p_strTo) {
+        return InstallFileFromMod(p_strFrom, p_strTo);
+    }
+
+    /// <summary>
+    /// Installs the speified file from the mod to the file system.
+    /// </summary>
+    /// <param name="p_strFile">The path of the file to install.</param>
+    /// <returns><c>true</c> if the file was written; <c>false</c> otherwise.</returns>
+    static bool InstallFileFromFomod(String^ p_strFile) {
+        return InstallFileFromMod(p_strFile, p_strFile);
+    }
+
+    /// <summary>
+    /// Retrieves the list of files in the mod.
+    /// </summary>
+    /// <returns>The list of files in the mod.</returns>
+    static array<String^>^ GetModFileList();
+
+    /// <summary>
+    /// Retrieves the list of files in the mod.
+    /// </summary>
+    /// <returns>The list of files in the mod.</returns>
+    static array<String^>^ GetFomodFileList() {
+        return GetModFileList();
+    }
+
+    /// <summary>
+    /// Retrieves the specified file from the mod.
+    /// </summary>
+    /// <param name="p_strFile">The file to retrieve.</param>
+    /// <returns>The requested file data.</returns>
+    static array<Byte>^ GetFileFromMod(String^ p_strFile);
+
+    /// <summary>
+    /// Retrieves the specified file from the mod.
+    /// </summary>
+    /// <param name="p_strFile">The file to retrieve.</param>
+    /// <returns>The requested file data.</returns>
+    static array<Byte>^ GetFileFromFomod(String^ p_strFile) {
+        return GetFileFromMod(p_strFile);
+    }
+
+    /// <summary>
+    /// Gets a filtered list of all files in a user's Data directory.
+    /// </summary>
+    /// <param name="p_strPath">The subdirectory of the Data directory from which to get the listing.</param>
+    /// <param name="p_strPattern">The pattern against which to filter the file paths.</param>
+    /// <param name="p_booAllFolders">Whether or not to search through subdirectories.</param>
+    /// <returns>A filtered list of all files in a user's Data directory.</returns>
+    static array<String^>^ GetExistingDataFileList(String^ p_strPath, String^ p_strPattern, bool p_booAllFolders);
+
+    /// <summary>
+    /// Determines if the specified file exists in the user's Data directory.
+    /// </summary>
+    /// <param name="p_strPath">The path of the file whose existence is to be verified.</param>
+    /// <returns><c>true</c> if the specified file exists; <c>false</c>
+    /// otherwise.</returns>
+    static bool DataFileExists(String^ p_strPath);
+
+    /// <summary>
+    /// Gets the speified file from the user's Data directory.
+    /// </summary>
+    /// <param name="p_strPath">The path of the file to retrieve.</param>
+    /// <returns>The specified file, or <c>null</c> if the file does not exist.</returns>
+    static array<Byte>^ GetExistingDataFile(String^ p_strPath);
+
+    /// <summary>
+    /// Writes the file represented by the given byte array to the given path.
+    /// </summary>
+    /// <remarks>
+    /// This method writes the given data as a file at the given path. If the file
+    /// already exists the user is prompted to overwrite the file.
+    /// </remarks>
+    /// <param name="p_strPath">The path where the file is to be created.</param>
+    /// <param name="p_bteData">The data that is to make up the file.</param>
+    /// <returns><c>true</c> if the file was written; <c>false</c> otherwise.</returns>
+    static bool GenerateDataFile(String^ p_strPath, array<Byte>^ p_bteData);
+
+    /// <summary>
+    /// Shows a message box with the given message.
+    /// </summary>
+    /// <param name="p_strMessage">The message to display in the message box.</param>
+    static void MessageBox(String^ p_strMessage) {
+      MessageBox(p_strMessage, nullptr);
+    }
+
+    /// <summary>
+    /// Shows a message box with the given message and title.
+    /// </summary>
+    /// <param name="p_strMessage">The message to display in the message box.</param>
+    /// <param name="p_strTitle">The message box's title, display in the title bar.</param>
+    static void MessageBox(String^ p_strMessage, String^ p_strTitle) {
+      MessageBox(p_strMessage, p_strTitle, MessageBoxButtons::OK);
+    }
+
+    /// <summary>
+    /// Shows a message box with the given message, title, and buttons.
+    /// </summary>
+    /// <param name="p_strMessage">The message to display in the message box.</param>
+    /// <param name="p_strTitle">The message box's title, display in the title bar.</param>
+    /// <param name="p_mbbButtons">The buttons to show in the message box.</param>
+    static DialogResult MessageBox(String^ p_strMessage, String^ p_strTitle, MessageBoxButtons p_mbbButtons) {
+      return MessageBox(p_strMessage, p_strTitle, p_mbbButtons, MessageBoxIcon::Information);
+    }
+
+    static DialogResult MessageBox(String^ p_strMessage, String^ p_strTitle, MessageBoxButtons p_mbbButtons, MessageBoxIcon p_mdiIcon) {
+      return ExtendedMessageBox(p_strMessage, p_strTitle, nullptr, p_mbbButtons, p_mdiIcon);
+    }
+
+    /// <summary>
+    /// Shows an extended message box with the given message, title, details, buttons, and icon.
+    /// </summary>
+    /// <param name="p_strMessage">The message to display in the message box.</param>
+    /// <param name="p_strTitle">The message box's title, displayed in the title bar.</param>
+    /// <param name="p_strDetails">The message box's details, displayed in the details area.</param>
+    /// <param name="p_mbbButtons">The buttons to show in the message box.</param>
+    /// <param name="p_mdiIcon">The icon to display in the message box.</param>
+    static DialogResult ExtendedMessageBox(String^ p_strMessage, String^ p_strTitle, String^ p_strDetails, MessageBoxButtons p_mbbButtons, MessageBoxIcon p_mdiIcon);
+
+    /// <summary>
+    /// Displays a selection form to the user.
+    /// </summary>
+    /// <param name="p_sopOptions">The options from which to select.</param>
+    /// <param name="p_strTitle">The title of the selection form.</param>
+    /// <param name="p_booSelectMany">Whether more than one item can be selected.</param>
+    /// <returns>The indices of the selected items.</returns>
+    static array<int>^ Select(array<SelectOption^>^ p_sopOptions, String^ p_strTitle, bool p_booSelectMany);
+
+    /// <summary>
+    /// Displays a selection form to the user.
+    /// </summary>
+    /// <remarks>
+    /// The items, previews, and descriptions are repectively ordered. In other words,
+    /// the i-th item in <paramref name="p_strItems"/> uses the i-th preview in
+    /// <paramref name="p_strPreviewPaths"/> and the i-th description in <paramref name="p_strDescriptions"/>.
+    ///
+    /// Similarly, the idices return as results correspond to the indices of the items in
+    /// <paramref name="p_strItems"/>.
+    /// </remarks>
+    /// <param name="p_strItems">The items from which to select.</param>
+    /// <param name="p_strPreviewPaths">The preview image file names for the items.</param>
+    /// <param name="p_strDescriptions">The descriptions of the items.</param>
+    /// <param name="p_strTitle">The title of the selection form.</param>
+    /// <param name="p_booSelectMany">Whether more than one item can be selected.</param>
+    /// <returns>The indices of the selected items.</returns>
+    static array<int>^ Select(array<String^>^ p_strItems, array<String^>^ p_strPreviewPaths, array<String^>^ p_strDescriptions, String^ p_strTitle, bool p_booSelectMany) {
+      const int size = p_strItems->GetLength(0);
+      array<SelectOption^>^ options = gcnew array<SelectOption^>(size);
+      for (int i = 0; i < size; ++i) {
+        options[i] = gcnew SelectOption(p_strItems[i], p_strPreviewPaths[i], p_strDescriptions[i]);
+      }
+      return Select(options, p_strTitle, p_booSelectMany);
+    }
+
+    /// <summary>
+    /// Displays a selection form to the user.
+    /// </summary>
+    /// <remarks>
+    /// The items, previews, and descriptions are repectively ordered. In other words,
+    /// the i-th item in <paramref name="p_strItems"/> uses the i-th preview in
+    /// <paramref name="p_imgPreviews"/> and the i-th description in <paramref name="p_strDescriptions"/>.
+    ///
+    /// Similarly, the idices return as results correspond to the indices of the items in
+    /// <paramref name="p_strItems"/>.
+    /// </remarks>
+    /// <param name="p_strItems">The items from which to select.</param>
+    /// <param name="p_imgPreviews">The preview images for the items.</param>
+    /// <param name="p_strDescriptions">The descriptions of the items.</param>
+    /// <param name="p_strTitle">The title of the selection form.</param>
+    /// <param name="p_booSelectMany">Whether more than one item can be selected.</param>
+    /// <returns>The indices of the selected items.</returns>
+    static array<int>^ ImageSelect(array<String^>^ p_strItems, array<Image^>^ /* p_imgPreviews */, array<String^>^ p_strDescriptions, String^ p_strTitle, bool p_booSelectMany) {
+      return Select(p_strItems, gcnew array<String^>(p_strItems->Length), p_strDescriptions, p_strTitle, p_booSelectMany);
+    }
+
+    /// <summary>
+    /// Creates a form that can be used in custom mod scripts.
+    /// </summary>
+    /// <returns>A form that can be used in custom mod scripts.</returns>
+    static Form^ CreateCustomForm() {
+      Form^ form = gcnew Form;
+      return form;
+    }
+
+    /// <summary>
+    /// Gets the version of the mod manager.
+    /// </summary>
+    /// <returns>The version of the mod manager.</returns>
+    static System::Version^ GetModManagerVersion();
+
+    /// <summary>
+    /// Gets the version of the game that is installed.
+    /// </summary>
+    /// <returns>The version of the game, or <c>null</c> if Fallout
+    /// is not installed.</returns>
+    static System::Version^ GetGameVersion();
+
+    // This is not in the spec., but I do not see a point in checking each
+    // script extender in a different way.
+    static System::Version^ GetScriptExtenderVersion();
+
+    /// <summary>
+    /// Gets the script extender version or null if it's not installed
+    /// </summary>
+    /// <returns></returns>
+    static System::Version^ GetSkseVersion() {
+      return GetScriptExtenderVersion();
+    }
+
+    /// <summary>
+    /// Gets the script extender version or null if it's not installed
+    /// </summary>
+    /// <returns></returns>
+    static System::Version^ GetFoseVersion() {
+      return GetScriptExtenderVersion();
+    }
+
+    /// <summary>
+    /// Gets the script extender version or null if it's not installed
+    /// </summary>
+    /// <returns></returns>
+    static System::Version^ GetNvseVersion() {
+      return GetScriptExtenderVersion();
+    }
+
+    /// <summary>
+    /// Gets the version of the mod manager.
+    /// </summary>
+    /// <returns>The version of the mod manager.</returns>
+    static System::Version^ GetFommVersion() {
+      return GetModManagerVersion();
+    }
+
+    /// <summary>
+    /// Gets the version of the game that is installed.
+    /// </summary>
+    /// <returns>The version of the game, or <c>null</c> if Fallout
+    /// is not installed.</returns>
+    static System::Version^ GetFalloutVersion() {
+      // I think this is an old function... What Fallout anyway? So just going
+      // to return the game version, whatever current game.
+      return GetGameVersion();
+    }
+
+    /// <summary>
+    /// Determins if the script extender for the game is installed
+    /// (this checks for the script extender of the game for which the
+    /// mod is being installed)
+    /// </summary>
+    /// <returns></returns>
+    static bool ScriptExtenderPresent();
+
+    /// <summary>
+    /// Gets a list of all install plugins.
+    /// </summary>
+    /// <returns>A list of all install plugins.</returns>
+    static array<String^>^ GetAllPlugins();
+
+    /// <summary>
+    /// Retrieves a list of currently active plugins.
+    /// </summary>
+    /// <returns>A list of currently active plugins.</returns>
+    static array<String^>^ GetActivePlugins();
+
+    /// <summary>
+    /// Sets the activated status of a plugin (i.e., and esp or esm file).
+    /// </summary>
+    /// <param name="p_strPluginPath">The path to the plugin to activate or deactivate.</param>
+    /// <param name="p_booActivate">Whether to activate the plugin.</param>
+    static void SetPluginActivation(String^ /* p_strPluginPath */, bool /* p_booActivate */) {
+      // throw gcnew NotImplementedException("SetPluginActivation");
+    }
+
+    /// <summary>
+    /// Sets the load order of the specifid plugin.
+    /// </summary>
+    /// <param name="p_strPlugin">The path to the plugin file whose load order is to be set.</param>
+    /// <param name="p_intNewIndex">The new load order index of the plugin.</param>
+    static void SetPluginOrderIndex(String^ /* p_strPlugin */, int /* p_intNewIndex */) {
+      // throw gcnew NotImplementedException("SetPluginOrderIndex");
+    }
+
+    /// <summary>
+    /// Sets the load order of the plugins.
+    /// </summary>
+    /// <remarks>
+    /// Each plugin will be moved from its current index to its indices' position
+    /// in <paramref name="p_intPlugins"/>.
+    /// </remarks>
+    /// <param name="p_intPlugins">The new load order of the plugins. Each entry in this array
+    /// contains the current index of a plugin. This array must contain all current indices.</param>
+    static void SetLoadOrder(array<int>^ /* p_intPlugins */) {
+      // throw gcnew NotImplementedException("SetLoadOrder");
+    }
+
+    /// <summary>
+    /// Moves the specified plugins to the given position in the load order.
+    /// </summary>
+    /// <remarks>
+    /// Note that the order of the given list of plugins is not maintained. They are re-ordered
+    /// to be in the same order as they are in the before-operation load order. This, I think,
+    /// is somewhat counter-intuitive and may change, though likely not so as to not break
+    /// backwards compatibility.
+    /// </remarks>
+    /// <param name="p_intPlugins">The list of plugins to move to the given position in the
+    /// load order. Each entry in this array contains the current index of a plugin.</param>
+    /// <param name="p_intPosition">The position in the load order to which to move the specified
+    /// plugins.</param>
+    static void SetLoadOrder(array<int>^ /* p_intPlugins */, int /* p_intPosition */) {
+      // throw gcnew NotImplementedException("SetLoadOrder");
+    }
+
+    /// <summary>
+    /// Retrieves the specified settings value as a string.
+    /// </summary>
+    /// <param name="settingsFileName">The name of the settings file from which to retrieve the value.</param>
+    /// <param name="section">The section containing the value to retrieve.</param>
+    /// <param name="key">The key of the value to retrieve.</param>
+    /// <returns>The specified value as a string.</returns>
+    static String^ GetIniString(String^ settingsFileName, String^ section, String^ key);
+
+    /// <summary>
+    /// Retrieves the specified settings value as an integer.
+    /// </summary>
+    /// <param name="settingsFileName">The name of the settings file from which to retrieve the value.</param>
+    /// <param name="section">The section containing the value to retrieve.</param>
+    /// <param name="key">The key of the value to retrieve.</param>
+    /// <returns>The specified value as an integer.</returns>
+    static int GetIniInt(String^ settingsFileName, String^ section, String^ key);
+
+    /// <summary>
+    /// Retrieves the specified Fallout.ini value as a string.
+    /// </summary>
+    /// <param name="section">The section containing the value to retrieve.</param>
+    /// <param name="key">The key of the value to retrieve.</param>
+    /// <returns>The specified value as a string.</returns>
+    /// <seealso cref="GetFalloutIniInt(string, string)"/>
+    static String^ GetFalloutIniString(String^ section, String^ key) {
+      return GetIniString("Fallout.ini", section, key);
+    }
+
+    /// <summary>
+    /// Retrieves the specified Fallout.ini value as an integer.
+    /// </summary>
+    /// <param name="section">The section containing the value to retrieve.</param>
+    /// <param name="key">The key of the value to retrieve.</param>
+    /// <seealso cref="GetFalloutIniString(string, string)"/>
+    static int GetFalloutIniInt(String^ section, String^ key) {
+      return GetIniInt("Fallout.ini", section, key);
+    }
+
+    /// <summary>
+    /// Retrieves the specified FalloutPrefs.ini value as a string.
+    /// </summary>
+    /// <param name="p_strSection">The section containing the value to retrieve.</param>
+    /// <param name="p_strKey">The key of the value to retrieve.</param>
+    /// <returns>The specified value as a string.</returns>
+    /// <seealso cref="GetPrefsIniInt(string, string)"/>
+    static String^ GetPrefsIniString(String^ p_strSection, String^ p_strKey) {
+      // This looks wrong? Yes! But that's what used in other mod managers...
+      return GetIniString("FalloutPrefs.ini", p_strSection, p_strKey);
+    }
+
+    /// <summary>
+    /// Retrieves the specified FalloutPrefs.ini value as an integer.
+    /// </summary>
+    /// <param name="p_strSection">The section containing the value to retrieve.</param>
+    /// <param name="p_strKey">The key of the value to retrieve.</param>
+    /// <returns>The specified value as an integer.</returns>
+    /// <seealso cref="GetPrefsIniString(string, string)"/>
+    static int GetPrefsIniInt(String^ p_strSection, String^ p_strKey) {
+      // This looks wrong? Yes! But that's what used in other mod managers...
+      return GetIniInt("FalloutPrefs.ini", p_strSection, p_strKey);
+    }
+
+    /// <summary>
+    /// Sets the specified value in the specified Ini file to the given value.
+    /// </summary>
+    /// <param name="p_strSettingsFileName">The name of the settings file to edit.</param>
+    /// <param name="p_strSection">The section in the Ini file to edit.</param>
+    /// <param name="p_strKey">The key in the Ini file to edit.</param>
+    /// <param name="p_strValue">The value to which to set the key.</param>
+    /// <returns><c>true</c> if the value was set; <c>false</c>
+    /// if the user chose not to overwrite the existing value.</returns>
+    static bool EditIni(String^ p_strSettingsFileName, String^ p_strSection, String^ p_strKey, String^ p_strValue);
+
+    /// <summary>
+    /// Sets the specified value in the Fallout.ini file to the given value.
+    /// </summary>
+    /// <param name="p_strSection">The section in the Ini file to edit.</param>
+    /// <param name="p_strKey">The key in the Ini file to edit.</param>
+    /// <param name="p_strValue">The value to which to set the key.</param>
+    /// <param name="p_booSaveOld">Not used.</param>
+    /// <returns><c>true</c> if the value was set; <c>false</c>
+    /// if the user chose not to overwrite the existing value.</returns>
+    static bool EditFalloutINI(String^ p_strSection, String^ p_strKey, String^ p_strValue, bool /* p_booSaveOld */) {
+      return EditIni("Fallout.ini", p_strSection, p_strKey, p_strValue);
+    }
+
+  };
+
+  /**
+   * @brief Post-install script.
+   */
+  MOBase::IPluginInstaller::EInstallResult postInstall(std::shared_ptr<MOBase::IFileTree>& tree);
+}
+
+// BaseScript cannot be in a namespace:
+public ref struct SelectOption: public CSharp::SelectOption {
+  SelectOption(System::String^ item, System::String^ preview, System::String^ desc) :
+    CSharp::SelectOption(item, preview, desc) { }
+};
+public ref class BaseScript: public CSharp::BaseScriptImpl { };
+
+#endif
diff --git a/libs/installer_fomod_csharp/src/csharp_interface.cpp b/libs/installer_fomod_csharp/src/csharp_interface.cpp
new file mode 100644
index 0000000..91a4a0d
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/csharp_interface.cpp
@@ -0,0 +1,157 @@
+#include "csharp_interface.h"
+
+#include <fstream>
+#include <regex>
+#include <sstream>
+
+#include <uibase/log.h>
+
+#include "base_script.h"
+#include "csharp_utils.h"
+
+// clang-format off
+
+#using <System.dll>
+
+using namespace MOBase;
+
+/**
+ * This is a assembly resolve handler that does only one thing: returns the assembly
+ * containing BaseScript (usually the DLL) when requested.
+ *
+ * I don't know why this must be done manually... But I did not find any better solution.
+ */
+System::Reflection::Assembly^ currentDomain_AssemblyResolve(System::Object^, System::ResolveEventArgs^ args)
+{
+  using namespace System::Reflection;
+
+  try {
+    Assembly^ baseScriptAssembly = System::Reflection::Assembly::GetAssembly(BaseScript::typeid);
+    if (args->Name->Equals(baseScriptAssembly->FullName)) {
+      return baseScriptAssembly;
+    }
+  }
+  catch (...)
+  {
+  }
+
+  return nullptr;
+}
+
+IPluginInstaller::EInstallResult executeScript(System::String^ script) {
+
+  using namespace System;
+  using namespace System::CodeDom;
+  using namespace System::CodeDom::Compiler;
+  using namespace System::Collections::Generic;
+
+  AppDomain^ currentDomain = AppDomain::CurrentDomain;
+  currentDomain->AssemblyResolve += gcnew ResolveEventHandler(currentDomain_AssemblyResolve);
+
+  // From Nexus-Mods/fomod-installer:
+  Dictionary<String^, String^>^ dicOptions = gcnew Dictionary<String^, String^>(10);
+  dicOptions->Add("CompilerVersion", "v4.0");
+
+  // List of assemblies (including BaseScript) - From Nexus-Mods/fomod-installer:
+  array<String^>^ referenceAssemblies = {
+    "System.dll",
+    "System.Runtime.dll",
+    "System.Drawing.dll",
+    "System.Windows.Forms.dll",
+    "System.Xml.dll",
+    System::Reflection::Assembly::GetAssembly(BaseScript::typeid)->Location
+  };
+
+  CompilerParameters^ cp = gcnew CompilerParameters(referenceAssemblies);
+  cp->GenerateExecutable = false;
+  cp->IncludeDebugInformation = false;
+  cp->GenerateInMemory = true;
+  cp->TreatWarningsAsErrors = false;
+  CodeDomProvider^ provider = CodeDomProvider::CreateProvider("CSharp", dicOptions);
+
+  // Compile the script
+  auto result = provider->CompileAssemblyFromSource(cp, script);
+
+  int errorCount = 0;
+  for each (CompilerError ^ error in result->Errors) {
+    if (error->IsWarning) {
+      log::warn("C# [{}]: {}", error->Line, CSharp::to_string(error->ErrorText));
+    }
+    else {
+      log::error("C# [{}]: {}", error->Line, CSharp::to_string(error->ErrorText));
+      ++errorCount;
+    }
+  }
+
+  if (errorCount > 0) {
+    return IPluginInstaller::EInstallResult::RESULT_FAILED;
+  }
+
+  // Execute the script:
+  try {
+    auto scriptClass = result->CompiledAssembly->GetType("Script");
+    BaseScript^ scriptObject = (BaseScript^)System::Activator::CreateInstance(scriptClass);
+    auto onActivateMethod = scriptObject->GetType()->GetMethod("OnActivate");
+
+    auto success = (bool)(onActivateMethod->IsStatic ? onActivateMethod->Invoke(nullptr, nullptr) : onActivateMethod->Invoke(scriptObject, nullptr));
+    return success ? IPluginInstaller::EInstallResult::RESULT_SUCCESS : IPluginInstaller::EInstallResult::RESULT_CANCELED;
+  }
+  catch (System::Exception^ ex) {
+    log::error("C# ({}): {}\n{}", CSharp::to_string(ex->GetType()->FullName), CSharp::to_string(ex->Message), CSharp::to_string(ex->StackTrace));
+    System::Exception^ innerEx = ex->InnerException;
+    if (innerEx) {
+      log::error("C# ({}): {}\n{}", CSharp::to_string(innerEx->GetType()->FullName), CSharp::to_string(innerEx->Message), CSharp::to_string(innerEx->StackTrace));
+    }
+    return IPluginInstaller::EInstallResult::RESULT_FAILED;
+  }
+
+}
+
+namespace CSharp {
+
+  IPluginInstaller::EInstallResult executeCSharpScript(QString scriptPath, std::shared_ptr<IFileTree>& tree) {
+
+    using namespace System;
+    using namespace System::IO;
+    using namespace System::Text::RegularExpressions;
+
+    // Note: Using C# stuff here to mimicate NMM since there are some encoding issues, and
+    // some regex do not work in C++:
+    array<Byte>^ scriptBytes = File::ReadAllBytes(from_string(scriptPath.toStdWString()));
+
+    // Read the script (using C# to "auto-detect" encoding in a C# way):
+    String^ script;
+    {
+      auto memoryStream = gcnew MemoryStream(scriptBytes);
+      auto reader = gcnew StreamReader(memoryStream, true);
+
+      script = reader->ReadToEnd();
+
+      reader->Close();
+      memoryStream->Close();
+
+      delete reader;
+      delete memoryStream;
+    }
+
+
+    Regex^ regScriptClass = gcnew Regex(R"re((class\s+Script\s*:.*?)(\S*BaseScript))re");
+    Regex^ regFommUsing = gcnew Regex(R"re(\s*using\s*fomm.Scripting\s*;)re");
+
+    String^ strBaseScriptClassName = regScriptClass->Match(script)->Groups[2]->ToString();
+    Regex^ regOtherScriptClasses = gcnew Regex(String::Format(R"re((class\s+\S+\s*:.*?)(?<!\w){0})re", strBaseScriptClassName));
+    String^ strCode = script;
+    strCode = regScriptClass->Replace(strCode, "$1BaseScript");
+    strCode = regOtherScriptClasses->Replace(strCode, "$1BaseScript");
+    strCode = regFommUsing->Replace(strCode, "");
+
+    auto result = executeScript(strCode);
+
+    if (result != IPluginInstaller::EInstallResult::RESULT_SUCCESS) {
+      return result;
+    }
+
+    return postInstall(tree);
+  }
+
+}
diff --git a/libs/installer_fomod_csharp/src/csharp_interface.h b/libs/installer_fomod_csharp/src/csharp_interface.h
new file mode 100644
index 0000000..4f22c20
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/csharp_interface.h
@@ -0,0 +1,40 @@
+#ifndef CSHARP_INTERFACE_H
+#define CSHARP_INTERFACE_H
+
+#include <map>
+
+#include <uibase/ifiletree.h>
+#include <uibase/iplugininstaller.h>
+
+namespace CSharp
+{
+
+void init(MOBase::IOrganizer* moInfo);
+
+/**
+ * @brief Initialize the C# interface before starting an installation.
+ *
+ * @param installer The FOMOD C# installer.
+ * @param manager The installation manager from the installer.
+ * @param parentWidget The parent widget from the installer.
+ * @param tree The archive tree.
+ * @param extractedEntries A map from extracted entries to their extracted path.
+ */
+void beforeInstall(
+    MOBase::IPlugin const* installer, MOBase::IInstallationManager* manager,
+    QWidget* parentWidget, std::shared_ptr<MOBase::IFileTree> tree,
+    std::map<std::shared_ptr<const MOBase::FileTreeEntry>, QString> extractedEntries);
+
+/**
+ * @brief Clear the C# interface after an installation.
+ *
+ * @param scriptPath Path to the script to execute.
+ * @param tree Reference where the final tree will be stored (in case of success.
+ *
+ * @return the installation result after performing post-installation.
+ */
+MOBase::IPluginInstaller::EInstallResult
+executeCSharpScript(QString scriptPath, std::shared_ptr<MOBase::IFileTree>& tree);
+
+}  // namespace CSharp
+#endif
diff --git a/libs/installer_fomod_csharp/src/csharp_utils.h b/libs/installer_fomod_csharp/src/csharp_utils.h
new file mode 100644
index 0000000..5ede874
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/csharp_utils.h
@@ -0,0 +1,41 @@
+// clang-format off
+
+#ifndef CSHARP_UTILS_H
+#define CSHARP_UTILS_H
+
+#include <type_traits>
+#include <string>
+
+#include <QString>
+
+#include <msclr\marshal_cppstd.h>
+
+#using <System.dll>
+
+namespace CSharp {
+
+  /**
+   * Handy functions.
+   */
+  inline std::string to_string(System::String^ value) {
+    return msclr::interop::marshal_as<std::string>(value);
+  }
+  inline std::wstring to_wstring(System::String^ value) {
+    return msclr::interop::marshal_as<std::wstring>(value);
+  }
+  inline QString to_qstring(System::String^ value) {
+    msclr::interop::marshal_context ctx;
+    return QString::fromWCharArray(ctx.marshal_as<const wchar_t*>(value));
+  }
+
+  template <class Str>
+  inline System::String^ from_string(Str const& string) {
+    return msclr::interop::marshal_as<System::String^>(string);
+  }
+  inline System::String^ from_string(QString const& string) {
+    return msclr::interop::marshal_as<System::String^>(string.toStdWString().c_str());
+  }
+
+}
+
+#endif
diff --git a/libs/installer_fomod_csharp/src/installer_fomod_csharp.cpp b/libs/installer_fomod_csharp/src/installer_fomod_csharp.cpp
new file mode 100644
index 0000000..02d3a3e
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/installer_fomod_csharp.cpp
@@ -0,0 +1,193 @@
+/*
+Copyright (C) 2020 Holt59. All rights reserved.
+
+Mod Organizer is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Mod Organizer is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Mod Organizer.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <uibase/iinstallationmanager.h>
+
+#include "csharp_interface.h"
+#include "installer_fomod_csharp.h"
+#include "installer_fomod_predialog.h"
+#include "xml_info_reader.h"
+
+using namespace MOBase;
+
+bool InstallerFomodCSharp::init(IOrganizer* moInfo)
+{
+  m_MOInfo = moInfo;
+  CSharp::init(moInfo);
+  return true;
+}
+
+std::shared_ptr<const IFileTree>
+InstallerFomodCSharp::findFomodDirectory(std::shared_ptr<const IFileTree> tree) const
+{
+  auto entry = tree->find("fomod", FileTreeEntry::DIRECTORY);
+
+  if (entry != nullptr) {
+    return entry->astree();
+  }
+
+  if (tree->empty()) {
+    return nullptr;
+  }
+
+  // We need at least a directory:
+  if (!tree->at(0)->isDir()) {
+    return nullptr;
+  }
+
+  // But not two:
+  if (tree->size() > 1 && tree->at(1)->isDir()) {
+    return nullptr;
+  }
+
+  return findFomodDirectory(tree->at(0)->astree());
+}
+
+std::shared_ptr<const FileTreeEntry>
+InstallerFomodCSharp::findScriptFile(std::shared_ptr<const IFileTree> tree) const
+{
+  auto fomodDirectory = findFomodDirectory(tree);
+
+  if (fomodDirectory == nullptr) {
+    return nullptr;
+  }
+
+  for (auto e : *fomodDirectory) {
+    if (e->isFile() && e->suffix().compare("cs", Qt::CaseInsensitive) == 0) {
+      return e;
+    }
+  }
+
+  return nullptr;
+}
+
+std::shared_ptr<const FileTreeEntry>
+InstallerFomodCSharp::findInfoFile(std::shared_ptr<const IFileTree> tree) const
+{
+  auto fomodDirectory = findFomodDirectory(tree);
+
+  if (fomodDirectory == nullptr) {
+    return nullptr;
+  }
+
+  for (auto e : *fomodDirectory) {
+    if (e->isFile() && e->compare("info.xml") == 0) {
+      return e;
+    }
+  }
+
+  return nullptr;
+}
+
+bool InstallerFomodCSharp::isArchiveSupported(
+    std::shared_ptr<const MOBase::IFileTree> tree) const
+{
+  return findScriptFile(tree) != nullptr;
+}
+
+InstallerFomodCSharp::EInstallResult
+InstallerFomodCSharp::install(MOBase::GuessedValue<QString>& modName,
+                              std::shared_ptr<MOBase::IFileTree>& tree,
+                              QString& version, int& modID)
+{
+  static std::set<QString, FileNameComparator> imageSuffixes{"png", "jpg", "jpeg",
+                                                             "gif", "bmp"};
+
+  // Extract the script file:
+  auto scriptFile = findScriptFile(tree);
+  if (scriptFile == nullptr) {
+    return EInstallResult::RESULT_NOTATTEMPTED;
+  }
+
+  // Check if there is a info.xml:
+  auto infoFile = findInfoFile(tree);
+
+  // Set containing everything to extract except the script and the info file:
+  std::set<std::shared_ptr<const FileTreeEntry>> toExtractSet{scriptFile};
+
+  if (infoFile != nullptr) {
+    toExtractSet.insert(infoFile);
+  }
+
+  // Extract all the images:
+  tree->walk([&](const QString&, auto entry) {
+    if (entry->isFile() && imageSuffixes.count(entry->suffix()) > 0) {
+      toExtractSet.insert(entry);
+    }
+    return IFileTree::WalkReturn::CONTINUE;
+  });
+
+  // Extract everything from the fomod/ folder:
+  auto fomodFolder = findFomodDirectory(tree);
+  fomodFolder->walk([&](const QString&, auto entry) {
+    if (entry->isFile()) {
+      toExtractSet.insert(entry);
+    }
+    return IFileTree::WalkReturn::CONTINUE;
+  });
+
+  // Convert to vector:
+  std::vector toExtract(std::begin(toExtractSet), std::end(toExtractSet));
+  QStringList paths(manager()->extractFiles(toExtract));
+
+  // If user cancelled:
+  if (toExtract.size() != static_cast<std::size_t>(paths.size())) {
+    return EInstallResult::RESULT_CANCELED;
+  }
+
+  // Create a map from entry to file path:
+  std::map<std::shared_ptr<const FileTreeEntry>, QString> entryToPath;
+  for (std::size_t i = 0; i < toExtract.size(); ++i) {
+    entryToPath[toExtract[i]] = paths[i];
+  }
+
+  if (infoFile != nullptr) {
+    QFile file(entryToPath[infoFile]);
+    if (file.open(QIODevice::ReadOnly)) {
+      auto info = FomodInfoReader::readXml(file, &FomodInfoReader::parseInfo);
+      if (!std::get<0>(info).isEmpty()) {
+        modName.update(std::get<0>(info), GUESS_META);
+      }
+      if (std::get<1>(info) != -1) {
+        modID = std::get<1>(info);
+      }
+      if (!std::get<2>(info).isEmpty()) {
+        version = std::get<2>(info);
+      }
+    }
+  }
+
+  // Show the dialog:
+  InstallerFomodPredialog dialog(modName, parentWidget());
+  if (dialog.exec() != QDialog::Accepted) {
+    if (dialog.manualRequested()) {
+      modName.update(dialog.getName(), GUESS_USER);
+      return EInstallResult::RESULT_MANUALREQUESTED;
+    } else {
+      return EInstallResult::RESULT_CANCELED;
+    }
+  }
+  modName.update(dialog.getName(), GUESS_USER);
+
+  // Run the C# script:
+  const QString scriptPath = entryToPath[scriptFile];
+  CSharp::beforeInstall(
+      this, manager(), parentWidget(),
+      std::const_pointer_cast<IFileTree>(scriptFile->parent()->parent()),
+      std::move(entryToPath));
+  return CSharp::executeCSharpScript(scriptPath, tree);
+}
diff --git a/libs/installer_fomod_csharp/src/installer_fomod_csharp.h b/libs/installer_fomod_csharp/src/installer_fomod_csharp.h
new file mode 100644
index 0000000..530db37
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/installer_fomod_csharp.h
@@ -0,0 +1,84 @@
+/*
+Copyright (C) 2020 Holt59. All rights reserved.
+
+Mod Organizer is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Mod Organizer is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Mod Organizer.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef INSTALLER_FOMOD_CSHARP_H
+#define INSTALLER_FOMOD_CSHARP_H
+
+#include <uibase/iplugininstallersimple.h>
+
+class InstallerFomodCSharp : public MOBase::IPluginInstallerSimple
+{
+  Q_OBJECT
+  Q_INTERFACES(MOBase::IPlugin MOBase::IPluginInstaller MOBase::IPluginInstallerSimple)
+  Q_PLUGIN_METADATA(IID "org.holt59.InstallerFomodCSharp")
+
+public:
+  InstallerFomodCSharp() {}
+
+  virtual bool init(MOBase::IOrganizer* moInfo) override;
+
+  virtual QString name() const override { return "Fomod Installer C#"; }
+
+  virtual QString localizedName() const override { return tr("Fomod Installer C#"); }
+
+  virtual QString author() const override { return "Holt59"; }
+
+  virtual QString description() const override
+  {
+    return tr("Installer for C# based FOMOD archives.");
+  }
+
+  virtual MOBase::VersionInfo version() const override
+  {
+    return MOBase::VersionInfo(1, 0, 0, MOBase::VersionInfo::RELEASE_BETA);
+  }
+
+  virtual QList<MOBase::PluginSetting> settings() const override
+  {
+    return {
+        MOBase::PluginSetting("enabled", "check to enable this plugin", QVariant(true)),
+        MOBase::PluginSetting("prefer", "prefer this over the NCC based plugin",
+                              QVariant(true))};
+  }
+
+  virtual unsigned int priority() const override
+  {
+    // It's the same priority as the FOMOD installer but those should never conflict:
+    return m_MOInfo->pluginSetting(name(), "prefer").toBool() ? 110 : 90;
+  }
+
+  virtual bool isManualInstaller() const override { return false; }
+
+  virtual bool
+  isArchiveSupported(std::shared_ptr<const MOBase::IFileTree> tree) const override;
+
+  virtual EInstallResult install(MOBase::GuessedValue<QString>& modName,
+                                 std::shared_ptr<MOBase::IFileTree>& tree,
+                                 QString& version, int& modID) override;
+
+private:
+  MOBase::IOrganizer* m_MOInfo;
+
+  std::shared_ptr<const MOBase::IFileTree>
+  findFomodDirectory(std::shared_ptr<const MOBase::IFileTree> tree) const;
+  std::shared_ptr<const MOBase::FileTreeEntry>
+  findScriptFile(std::shared_ptr<const MOBase::IFileTree> tree) const;
+  std::shared_ptr<const MOBase::FileTreeEntry>
+  findInfoFile(std::shared_ptr<const MOBase::IFileTree> tree) const;
+};
+
+#endif
diff --git a/libs/installer_fomod_csharp/src/installer_fomod_csharp_en.ts b/libs/installer_fomod_csharp/src/installer_fomod_csharp_en.ts
new file mode 100644
index 0000000..7c13b6c
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/installer_fomod_csharp_en.ts
@@ -0,0 +1,125 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE TS>
+<TS version="2.1" language="en_US">
+<context>
+    <name>FomodCSharpPostDialog</name>
+    <message>
+        <location filename="installer_fomod_csharp_postdialog.ui" line="14"/>
+        <source>Settings modification required</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_postdialog.ui" line="20"/>
+        <source>The installer needs to edit the following settings. You can either apply them, discard them or move them to the mod installation folder (under INI Tweaks).</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_postdialog.ui" line="56"/>
+        <source>Apply the settings to the INI files corresponding to the current profile.</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_postdialog.ui" line="59"/>
+        <source>Apply</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_postdialog.ui" line="66"/>
+        <source>Discard the settings.</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_postdialog.ui" line="69"/>
+        <source>Discard</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_postdialog.ui" line="76"/>
+        <source>Create files under &quot;INI Tweaks&quot; in the mod folder with these settings.</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_postdialog.ui" line="79"/>
+        <source>INI Tweaks</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_postdialog.ui" line="86"/>
+        <source>Cancel the installation.</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_postdialog.ui" line="89"/>
+        <source>Cancel</source>
+        <translation type="unfinished"></translation>
+    </message>
+</context>
+<context>
+    <name>FomodCSharpPredialog</name>
+    <message>
+        <location filename="installer_fomod_csharp_predialog.ui" line="14"/>
+        <source>FOMOD C# Installer</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_predialog.ui" line="22"/>
+        <source>Name</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_predialog.ui" line="40"/>
+        <location filename="installer_fomod_csharp_predialog.ui" line="43"/>
+        <source>Opens a Dialog that allows custom modifications.</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_predialog.ui" line="46"/>
+        <source>Manual</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_predialog.ui" line="69"/>
+        <source>Start</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp_predialog.ui" line="79"/>
+        <source>Cancel</source>
+        <translation type="unfinished"></translation>
+    </message>
+</context>
+<context>
+    <name>FomodInfoReader</name>
+    <message>
+        <location filename="xml_info_reader.h" line="109"/>
+        <source>Failed to parse %1. See console for details.</source>
+        <translation type="unfinished"></translation>
+    </message>
+</context>
+<context>
+    <name>InstallerFomodCSharp</name>
+    <message>
+        <location filename="installer_fomod_csharp.h" line="36"/>
+        <source>Fomod Installer C#</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="installer_fomod_csharp.h" line="42"/>
+        <source>Installer for C# based FOMOD archives.</source>
+        <translation type="unfinished"></translation>
+    </message>
+</context>
+<context>
+    <name>QObject</name>
+    <message>
+        <location filename="base_script.cpp" line="516"/>
+        <source>Choose any:</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="base_script.cpp" line="519"/>
+        <source>Choose one:</source>
+        <translation type="unfinished"></translation>
+    </message>
+</context>
+</TS>
diff --git a/libs/installer_fomod_csharp/src/installer_fomod_csharp_postdialog.ui b/libs/installer_fomod_csharp/src/installer_fomod_csharp_postdialog.ui
new file mode 100644
index 0000000..89a6106
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/installer_fomod_csharp_postdialog.ui
@@ -0,0 +1,99 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>FomodCSharpPostDialog</class>
+ <widget class="QDialog" name="FomodCSharpPostDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>589</width>
+    <height>399</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Settings modification required</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QLabel" name="label">
+     <property name="text">
+      <string>The installer needs to edit the following settings. You can either apply them, discard them or move them to the mod installation folder (under INI Tweaks).</string>
+     </property>
+     <property name="wordWrap">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <layout class="QHBoxLayout" name="horizontalLayout">
+     <item>
+      <widget class="QTabWidget" name="tabWidget">
+       <property name="currentIndex">
+        <number>-1</number>
+       </property>
+      </widget>
+     </item>
+    </layout>
+   </item>
+   <item>
+    <layout class="QHBoxLayout" name="horizontalLayout_2" stretch="0,0,0,0,0">
+     <item>
+      <spacer name="horizontalSpacer">
+       <property name="orientation">
+        <enum>Qt::Horizontal</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>40</width>
+         <height>20</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
+     <item>
+      <widget class="QPushButton" name="applyBtn">
+       <property name="toolTip">
+        <string>Apply the settings to the INI files corresponding to the current profile.</string>
+       </property>
+       <property name="text">
+        <string>Apply</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QPushButton" name="discardBtn">
+       <property name="toolTip">
+        <string>Discard the settings.</string>
+       </property>
+       <property name="text">
+        <string>Discard</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QPushButton" name="moveBtn">
+       <property name="toolTip">
+        <string>Create files under &quot;INI Tweaks&quot; in the mod folder with these settings.</string>
+       </property>
+       <property name="text">
+        <string>INI Tweaks</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QPushButton" name="cancelBtn">
+       <property name="toolTip">
+        <string>Cancel the installation.</string>
+       </property>
+       <property name="text">
+        <string>Cancel</string>
+       </property>
+      </widget>
+     </item>
+    </layout>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/libs/installer_fomod_csharp/src/installer_fomod_csharp_predialog.ui b/libs/installer_fomod_csharp/src/installer_fomod_csharp_predialog.ui
new file mode 100644
index 0000000..0aa08c3
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/installer_fomod_csharp_predialog.ui
@@ -0,0 +1,89 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>FomodCSharpPredialog</class>
+ <widget class="QDialog" name="FomodCSharpPredialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>83</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>FOMOD C# Installer</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <layout class="QHBoxLayout" name="horizontalLayout" stretch="0,1">
+     <item>
+      <widget class="QLabel" name="label">
+       <property name="text">
+        <string>Name</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QComboBox" name="nameCombo">
+       <property name="editable">
+        <bool>true</bool>
+       </property>
+      </widget>
+     </item>
+    </layout>
+   </item>
+   <item>
+    <layout class="QHBoxLayout" name="horizontalLayout_2">
+     <item>
+      <widget class="QPushButton" name="manualBtn">
+       <property name="toolTip">
+        <string>Opens a Dialog that allows custom modifications.</string>
+       </property>
+       <property name="whatsThis">
+        <string>Opens a Dialog that allows custom modifications.</string>
+       </property>
+       <property name="text">
+        <string>Manual</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <spacer name="horizontalSpacer">
+       <property name="orientation">
+        <enum>Qt::Horizontal</enum>
+       </property>
+       <property name="sizeType">
+        <enum>QSizePolicy::MinimumExpanding</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>20</width>
+         <height>20</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
+     <item>
+      <widget class="QPushButton" name="okBtn">
+       <property name="text">
+        <string>Start</string>
+       </property>
+       <property name="default">
+        <bool>true</bool>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QPushButton" name="cancelBtn">
+       <property name="text">
+        <string>Cancel</string>
+       </property>
+      </widget>
+     </item>
+    </layout>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/libs/installer_fomod_csharp/src/installer_fomod_postdialog.h b/libs/installer_fomod_csharp/src/installer_fomod_postdialog.h
new file mode 100644
index 0000000..9804610
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/installer_fomod_postdialog.h
@@ -0,0 +1,87 @@
+#ifndef INSTALLER_FOMOD_POSTDIALOG_H
+#define INSTALLER_FOMOD_POSTDIALOG_H
+
+#include "ui_installer_fomod_csharp_postdialog.h"
+
+#include <QTextEdit>
+
+#include "psettings.h"
+
+/**
+ * @brief Dialog for the installation of a simple archive
+ * a simple archive is one that doesn't require any manual changes to work correctly
+ **/
+class InstallerFomodPostDialog : public QDialog
+{
+  Q_OBJECT
+
+public:
+  enum class Result
+  {
+    APPLY,
+    DISCARD,
+    MOVE,
+  };
+
+  /**
+   * @brief constructor
+   *
+   * @param preset suggested name for the mod
+   * @param parent parent widget
+   **/
+  explicit InstallerFomodPostDialog(QWidget* parent = 0)
+      : QDialog(parent), ui(new Ui::FomodCSharpPostDialog)
+  {
+    ui->setupUi(this);
+    setWindowFlags(windowFlags() & (~Qt::WindowContextHelpButtonHint));
+  }
+
+  ~InstallerFomodPostDialog() {}
+
+  /**
+   * @return the result of this dialog if the user did not cancel.
+   */
+  Result result() const { return m_Result; }
+
+  /**
+   *
+   */
+  void setIniSettings(std::map<QString, PSettings> const& settings)
+  {
+    for (auto p : settings) {
+      QTextEdit* widget = new QTextEdit(this);
+      widget->append(p.second.toString());
+      widget->setReadOnly(true);
+      ui->tabWidget->addTab(widget, p.first);
+    }
+  }
+
+private slots:
+
+  void on_discardBtn_clicked()
+  {
+    m_Result = Result::DISCARD;
+    this->accept();
+  }
+
+  void on_applyBtn_clicked()
+  {
+    m_Result = Result::APPLY;
+    this->accept();
+  }
+
+  void on_moveBtn_clicked()
+  {
+    m_Result = Result::MOVE;
+    this->accept();
+  }
+
+  void on_cancelBtn_clicked() { this->reject(); }
+
+private:
+  std::unique_ptr<Ui::FomodCSharpPostDialog> ui;
+
+  Result m_Result{Result::APPLY};
+};
+
+#endif
diff --git a/libs/installer_fomod_csharp/src/installer_fomod_predialog.h b/libs/installer_fomod_csharp/src/installer_fomod_predialog.h
new file mode 100644
index 0000000..5c57fdf
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/installer_fomod_predialog.h
@@ -0,0 +1,72 @@
+#ifndef INSTALLER_FOMOD_PREDIALOG_H
+#define INSTALLER_FOMOD_PREDIALOG_H
+
+#include "ui_installer_fomod_csharp_predialog.h"
+
+#include <uibase/guessedvalue.h>
+
+#include <QCompleter>
+
+/**
+ * @brief Dialog for the installation of a simple archive
+ * a simple archive is one that doesn't require any manual changes to work correctly
+ **/
+class InstallerFomodPredialog : public QDialog
+{
+  Q_OBJECT
+
+public:
+  /**
+   * @brief constructor
+   *
+   * @param preset suggested name for the mod
+   * @param parent parent widget
+   **/
+  explicit InstallerFomodPredialog(const MOBase::GuessedValue<QString>& preset,
+                                   QWidget* parent = 0)
+      : QDialog(parent), ui(new Ui::FomodCSharpPredialog), m_Manual(false)
+  {
+
+    ui->setupUi(this);
+    setWindowTitle(preset + " - " + windowTitle());
+
+    for (auto iter = preset.variants().begin(); iter != preset.variants().end();
+         ++iter) {
+      ui->nameCombo->addItem(*iter);
+    }
+
+    ui->nameCombo->setCurrentIndex(ui->nameCombo->findText(preset));
+    setWindowFlags(windowFlags() & (~Qt::WindowContextHelpButtonHint));
+    ui->nameCombo->completer()->setCaseSensitivity(Qt::CaseSensitive);
+  }
+
+  ~InstallerFomodPredialog() {}
+
+  /**
+   * @return true if the user requested a manual installation.
+   **/
+  bool manualRequested() const { return m_Manual; }
+
+  /**
+   * @return the (user-modified) mod name
+   **/
+  QString getName() const { return ui->nameCombo->currentText(); }
+
+private slots:
+
+  void on_okBtn_clicked() { this->accept(); }
+
+  void on_cancelBtn_clicked() { this->reject(); }
+
+  void on_manualBtn_clicked()
+  {
+    m_Manual = true;
+    this->reject();
+  }
+
+private:
+  std::unique_ptr<Ui::FomodCSharpPredialog> ui;
+  bool m_Manual;
+};
+
+#endif
diff --git a/libs/installer_fomod_csharp/src/psettings.h b/libs/installer_fomod_csharp/src/psettings.h
new file mode 100644
index 0000000..649c7da
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/psettings.h
@@ -0,0 +1,108 @@
+#ifndef PSETTINGS_H
+#define PSETTINGS_H
+
+#include <QSettings>
+#include <QString>
+#include <map>
+
+/**
+ * This is a small class that can be used to store INI settings in memory since
+ * QSettings is a pain to use without an actual file.
+ *
+ * It is a much simpler structure since it stores everything as string.
+ */
+struct PSettings
+{
+
+  /**
+   *
+   */
+  PSettings() = default;
+
+public:  // Value read/write.
+  /**
+   * @brief Set the value of the given section/key.
+   *
+   * @param section The section of the value.
+   * @param key The key of the value.
+   * @param value The value to set.
+   */
+  void setValue(QString section, QString key, QString value)
+  {
+    m_Values[std::make_pair(section, key)] = value;
+  }
+
+  /**
+   * @brief Return the value at the given section/key.
+   *
+   * @param section The section of the value.
+   * @param key The key of the value.
+   *
+   * @return the corresponding value, or an empty string if the section/key does not
+   * exist.
+   */
+  QString value(QString section, QString key) const
+  {
+    auto it = m_Values.find(std::make_pair(section, key));
+    return it == m_Values.end() ? QString() : it->second;
+  }
+
+  /**
+   * @brief Check if the given section/key exists in these settings.
+   *
+   * @param section The section of the value.
+   * @param key The key of the value.
+   *
+   * @return true if the section/key exist.
+   */
+  bool hasValue(QString section, QString key) const
+  {
+    return m_Values.find(std::make_pair(section, key)) != m_Values.end();
+  }
+
+public:  // Output:
+  /**
+   * @brief Convert this PSettings to a string.
+   *
+   * @return a string representing the content of a valid INI file corresponding
+   *     to this PSettings.
+   */
+  QString toString() const
+  {
+    QString result = "";
+    QString cSection;
+    for (auto& p : m_Values) {
+      if (cSection != p.first.first) {
+        if (!cSection.isEmpty()) {
+          result += '\n';
+        }
+        cSection = p.first.first;
+        result += "[" + cSection + "]\n";
+      }
+      result += p.first.second + "=" + p.second + "\n";
+    }
+    return result;
+  }
+
+  /**
+   * @brief Update the given QSettings with all the value in this.
+   *
+   * @param settings The settings to update.
+   */
+  void update(QSettings& settings) const
+  {
+    for (auto& p : m_Values) {
+      if (p.first.first == "General") {
+        settings.setValue(p.first.second, p.second);
+      } else {
+        settings.setValue(p.first.first + "/" + p.first.second, p.second);
+      }
+    }
+  }
+
+private:
+  // Map from <section, key> to value:
+  std::map<std::pair<QString, QString>, QString> m_Values;
+};
+
+#endif  // !PSETTINGS_H
diff --git a/libs/installer_fomod_csharp/src/xml_info_reader.h b/libs/installer_fomod_csharp/src/xml_info_reader.h
new file mode 100644
index 0000000..91d6d9a
--- /dev/null
+++ b/libs/installer_fomod_csharp/src/xml_info_reader.h
@@ -0,0 +1,140 @@
+#ifndef XML_INFO_READER_H
+#define XML_INFO_READER_H
+
+#include <QFile>
+#include <QIODevice>
+#include <QString>
+#include <QStringEncoder>
+#include <QTextStream>
+#include <QXmlStreamReader>
+
+#include <uibase/log.h>
+#include <uibase/utility.h>
+
+// This is from installer_fomod, but should probably not be duplicated here.
+
+struct FomodInfoReader : QObject
+{
+
+  Q_OBJECT
+
+public:
+  struct XmlParseError : MOBase::Exception
+  {
+    XmlParseError(const QString& message) : MOBase::Exception(message) {}
+  };
+
+  static QByteArray skipXmlHeader(QIODevice& file)
+  {
+    static const unsigned char UTF16LE_BOM[] = {0xFF, 0xFE};
+    static const unsigned char UTF16BE_BOM[] = {0xFE, 0xFF};
+    static const unsigned char UTF8_BOM[]    = {0xEF, 0xBB, 0xBF};
+    static const unsigned char UTF16LE[]     = {0x3C, 0x00, 0x3F, 0x00};
+    static const unsigned char UTF16BE[]     = {0x00, 0x3C, 0x00, 0x3F};
+    static const unsigned char UTF8[]        = {0x3C, 0x3F, 0x78, 0x6D};
+
+    file.seek(0);
+    QByteArray rawBytes = file.read(4);
+    QTextStream stream(&file);
+    int bom = 0;
+    if (rawBytes.startsWith((const char*)UTF16LE_BOM)) {
+      stream.setEncoding(QStringEncoder::Encoding::Utf16LE);
+      bom = 2;
+    } else if (rawBytes.startsWith((const char*)UTF16BE_BOM)) {
+      stream.setEncoding(QStringEncoder::Encoding::Utf16BE);
+      bom = 2;
+    } else if (rawBytes.startsWith((const char*)UTF8_BOM)) {
+      stream.setEncoding(QStringEncoder::Encoding::Utf8);
+      bom = 3;
+    } else if (rawBytes.startsWith(QByteArray((const char*)UTF16LE, 4))) {
+      stream.setEncoding(QStringEncoder::Encoding::Utf16LE);
+    } else if (rawBytes.startsWith(QByteArray((const char*)UTF16BE, 4))) {
+      stream.setEncoding(QStringEncoder::Encoding::Utf16BE);
+    } else if (rawBytes.startsWith(QByteArray((const char*)UTF8, 4))) {
+      stream.setEncoding(QStringEncoder::Encoding::Utf8);
+    }  // otherwise maybe the textstream knows the encoding?
+
+    stream.seek(bom);
+    QString header = stream.readLine();
+    if (!header.startsWith("<?")) {
+      // it was all for nothing, there is no header here...
+      stream.seek(bom);
+    }
+    // this seems to be necessary due to buffering in QTextStream
+    file.seek(stream.pos());
+    return file.readAll();
+  }
+
+  template <class Fn>
+  static auto readXml(QFile& file, Fn&& fn)
+  {
+    // List of encodings to try:
+    static const std::vector<QStringConverter::Encoding> encodings{
+        QStringConverter::Utf16, QStringConverter::Utf8, QStringConverter::Latin1};
+
+    std::string errorMessage;
+    try {
+      QXmlStreamReader reader(&file);
+      return fn(reader);
+    } catch (const XmlParseError& e) {
+      MOBase::log::warn(
+          "The {} in this file is incorrectly encoded ({}). Applying heuristics...",
+          file.fileName(), e.what());
+    }
+
+    // nmm's xml parser is less strict than the one from qt and allows files with
+    // wrong encoding in the header. Being strict here would be bad user experience
+    // this works around bad headers.
+    QByteArray headerlessData = skipXmlHeader(file);
+
+    // try parsing the file with several encodings to support broken files
+    for (auto encoding : encodings) {
+      MOBase::log::debug("Trying encoding {} for {}... ",
+                         QStringConverter::nameForEncoding(encoding), file.fileName());
+      try {
+        QStringEncoder encoder(encoding);
+        QXmlStreamReader reader(
+            encoder.encode(QString("<?xml version=\"1.0\" encoding=\"%1\" ?>")
+                               .arg(encoder.name())) +
+            headerlessData);
+        MOBase::log::debug("Interpreting {} as {}.", file.fileName(), encoder.name());
+        return fn(reader);
+      } catch (const XmlParseError& e) {
+        MOBase::log::debug("Not {}: {}.", QStringConverter::nameForEncoding(encoding),
+                           e.what());
+      }
+    }
+
+    throw XmlParseError(
+        tr("Failed to parse %1. See console for details.").arg(file.fileName()));
+  }
+
+  static std::tuple<QString, int, QString> parseInfo(QXmlStreamReader& reader)
+  {
+    std::tuple<QString, int, QString> info{"", -1, ""};
+    while (!reader.atEnd()) {
+      switch (reader.readNext()) {
+      case QXmlStreamReader::StartElement: {
+        if (reader.name().toString() == "Name") {
+          std::get<0>(info) = reader.readElementText();
+        } else if (reader.name().toString() == "Author") {
+        } else if (reader.name().toString() == "Version") {
+          std::get<2>(info) = reader.readElementText();
+        } else if (reader.name().toString() == "Id") {
+          std::get<1>(info) = reader.readElementText().toInt();
+        } else if (reader.name().toString() == "Website") {
+        }
+      } break;
+      default: {
+      } break;
+      }
+    }
+    if (reader.hasError()) {
+      throw XmlParseError(
+          QString("%1 in line %2").arg(reader.errorString()).arg(reader.lineNumber()));
+    }
+    return info;
+  }
+};
+
+#endif
diff --git a/libs/installer_fomod_csharp/vcpkg.json b/libs/installer_fomod_csharp/vcpkg.json
new file mode 100644
index 0000000..28051ad
--- /dev/null
+++ b/libs/installer_fomod_csharp/vcpkg.json
@@ -0,0 +1,15 @@
+{
+  "features": {
+    "standalone": {
+      "description": "Build Standalone.",
+      "dependencies": ["mo2-cmake", "mo2-uibase"]
+    }
+  },
+  "vcpkg-configuration": {
+    "default-registry": {
+      "kind": "git",
+      "repository": "https://github.com/ModOrganizer2/vcpkg-registry",
+      "baseline": "8beb2e0efa9c17dd6d17bb05288dd1e40727f673"
+    }
+  }
+}