OpenAssetTools

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What OpenAssetTools is

OpenAssetTools (OAT) is a work-in-progress suite for creating mods and custom assets for older Call of Duty PC games. Its Unlinker opens supported game fastfiles and can dump some assets to disk, with available asset types varying by game. The Linker builds custom fastfiles and can reuse assets loaded from existing zones, although disk-readable asset types also differ across games. The guide covers IW3, IW4, IW5, T5, and T6, with progress varying by title. Listed formats include fastfiles (.ff), IWD files, IPak files, zone files, and scriptfile assets. The Unlinker works independently, without the game running; on Windows, users can drop a fastfile onto it. Both Linker and Unlinker provide command-line use. Zone project files use text-based, comma-separated key notation, with optional comments and C-like preprocessing. OAT is incomplete and currently offers only a subset of modding features. It is free and open source under GPLv3, with Windows and Linux support. Building requires Git and Premake; Windows also requires Visual Studio 2022, while Linux uses g++ and needs multilib for 32-bit builds on a 64-bit machine. The project says extracted game file contents remain the property of their respective owners, and that it is not affiliated with or endorsed by the named game companies.

Who it suits

OAT is for modders working with supported older Call of Duty PC titles who need tools to inspect assets or build custom fastfiles. Users should check the supported games and current extraction limits before relying on it.

What it does well

Linker builds custom fastfiles from existing zone assets.
Unlinker can run without the game running.
Both tools offer command-line use.
Supports Windows and Linux.
Free source code licensed under GPLv3.

What to know first

Project is incomplete and covers only a subset of modding features.
Available dumped and disk-readable assets vary by game.
Building requires Git and Premake.
Extracting files does not grant rights to their contents.

Limits

OpenAssetTools is incomplete and currently provides only a small subset of modding features. The assets that can be dumped or read from disk depend on the game.

Getting started

Open https://openassettools.dev/
Install Git and Premake
On Windows, install Visual Studio 2022
On Linux, install g++ and multilib for 32-bit builds
Build with the platform guide and its provided scripts
Run Unlinker or Linker from the command line, or drop a fastfile onto Unlinker on Windows

Verdict

OAT provides separate tools for extracting some supported assets and building custom fastfiles, but its coverage remains incomplete and varies by game. Check build requirements and rights to game contents before using it.

Questions

Is OpenAssetTools free?

Yes. It is free, open source, and licensed under GPLv3. No free trial is listed.

Which games does it support?

The guide covers PC versions of IW3, IW4, IW5, T5, and T6, with progress varying across those games.

Which platforms are supported?

OpenAssetTools supports Windows and Linux.

What can the Unlinker do?

It loads supported game fastfiles and dumps a subset of their assets to disk. It can run standalone without the game running.

What can the Linker do?

The Linker builds custom fastfiles and can reuse assets loaded from existing zones. Disk-readable asset types vary by game.

What files and formats are supported?

Supported formats include fastfiles (.ff), IWD files, IPak files, zone files, and scriptfile assets.

Facts from OpenAssetTools's own pages

Affiliation: The project states that it is not endorsed by or affiliated with Activision, Treyarch, Infinity Ward, or their descendants. · openassettools.dev, 9 Oct 2026
Asset creation: The site says users can create custom assets and mods for supported games. · openassettools.dev, 8 Oct 2026
Asset extraction: The Unlinker loads supported games’ fastfiles and can dump a subset of their assets to disk, depending on the game. · openassettools.dev, 8 Oct 2026
Asset formats: Unlinker dumps assets in formats intended to be close to the original game formats or in commonly used formats. · openassettools.dev, 9 Oct 2026
Build requirements: Building requires Git and Premake; the Windows guide specifies Visual Studio 2022, while the Linux guide specifies g++ and multilib for 32-bit builds. · openassettools.dev, 9 Oct 2026
Command line: The Linker and Unlinker both provide command-line usage, and the Unlinker can also be used by dragging and dropping a fastfile onto it on Windows. · openassettools.dev, 8 Oct 2026
Compatibility: The project aims to be compatible with existing formats and add support for previously unsupported titles. · openassettools.dev, 8 Oct 2026
Create fastfiles: The Linker builds custom fastfiles and can reuse assets loaded from existing zones. · openassettools.dev, 9 Oct 2026
Extract assets: The Unlinker can load supported fastfiles and dump a subset of their assets to disk, depending on the game. · openassettools.dev, 9 Oct 2026
Fastfile building: The Linker builds custom fastfiles and can reuse assets loaded from existing zones, although disk-readable asset types vary by game. · openassettools.dev, 8 Oct 2026
Legal note: The site says extracting game files does not grant rights to their contents, which remain with their respective owners. · openassettools.dev, 8 Oct 2026
Legal rights: The guide says extracting game file contents does not grant rights to those contents, which remain with their owners. · openassettools.dev, 9 Oct 2026
License: The source code is licensed under GPLv3. · openassettools.dev, 8 Oct 2026
Limits: The project is incomplete; only a subset of assets can currently be dumped or read from disk, depending on the game. · openassettools.dev, 9 Oct 2026
Linux build: Building on Linux requires Git and g++, with multilib needed for 32-bit builds on a 64-bit machine. · openassettools.dev, 8 Oct 2026
Linux use: The Linux build guide uses generate.sh to create make files, followed by make or the provided release or debug scripts. · openassettools.dev, 9 Oct 2026
Project files: Zone project files are text-based and use comma-separated key-based notation with optional comments and C-like preprocessing. · openassettools.dev, 9 Oct 2026
Project limits: The guide describes OAT as incomplete and says it currently provides only a small subset of modding features. · openassettools.dev, 8 Oct 2026
Purpose: OpenAssetTools is a work-in-progress modding tool suite for older Call of Duty titles. · openassettools.dev, 9 Oct 2026
Source license: The OAT source code is licensed under GPLv3. · openassettools.dev, 9 Oct 2026
Standalone operation: The Unlinker works standalone, and the homepage says running the game is not necessary to use the toolset. · openassettools.dev, 9 Oct 2026
Standalone use: The Unlinker works standalone, and the home page says running the game is not necessary. · openassettools.dev, 8 Oct 2026
Supported games: It currently supports the PC versions of Call of Duty 4: Modern Warfare, Modern Warfare 2, Modern Warfare 3, Black Ops, and Black Ops II, with varying progress across games. · openassettools.dev, 9 Oct 2026
Windows build: Building on Windows requires Git and Visual Studio 2022 according to the getting-started guide. · openassettools.dev, 8 Oct 2026

Where OpenAssetTools stands on Freedom251

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