# UELib (Unreal-Library)

> C# library that reads Unreal Engine 1, 2 and 3 package files such as .u, .upk and .udk, auto-detects a matching game build and deserializes their exports, imports and properties. Its main goal is decompiling UnrealScript bytecode back to source by reconstructing classes, states, functions, structs, enums and default properties; it also deserializes fonts, sounds, palettes and textures. The README’s per-game compatibility table runs from Unreal and Deus Ex to Splinter Cell, Mass Effect and the Batman: Arkham games, and the separate UE Explorer GUI is built on it.

- Type: Tool
- Targets: Game
- Category: Game analysis tools
- Relationship: Foundation tool
- Sources reviewed: 2026-10-20
- Added to the catalog: 2026-11-02
- Original resource: <https://github.com/EliotVU/Unreal-Library>
- Primary source: <https://github.com/EliotVU/Unreal-Library/blob/8236c39b79e30887a487ecf9b018204e430a5ebc/README.md>
- Catalog page: <https://awesomerea.org/resources/uelib-unreal-package-library/>
- Record JSON: <https://awesomerea.org/resources/uelib-unreal-package-library/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/uelib-unreal-package-library/index.md)

## Requirements & limits

- Published on NuGet as Eliot.UELib: the latest stable package at review is 1.13.7, published 2026-07-17, targeting .NET Framework 4.8, .NET Standard 2.0 and 2.1 and .NET 10, while the newest GitHub release page is 1.12.0 from 2025-09-22. Versions come from Nerdbank.GitVersioning, and the reviewed master commit (2026-10-16) is later than both. The repository also holds a small .NET 10 command-line client, a separate decompiler project and a work-in-progress T3D decompiler.
- Input is package files from the user’s own game installations. The README warns that opening an unsupported package could crash the system, that production UE3 packages are often compressed and must first be decompressed with a separate tool, and that some games need third-party decompression or extraction. Textures in .tfc caches, models and animations are not supported, and audio and texture output is expected to work for most games but not confirmed.
- Compatibility rows are the author’s and contributors’ reports per game and package version, including known problems such as bad output at function starts for X-COM: Alliance, wrong UStruct offsets for Duke Nukem Forever (2001) and bad byte-codes for Medal of Honor (2010); some rows are marked unverified. The MSTest suite reads TestUC1–TestUC3 packages compiled from the project’s own UnrealScript test classes, and some tests point at local Unreal Tournament or UT2004 installations.
- MIT license (Eliot van Uytfanghe). Game packages, scripts and assets keep their rights holders’ terms, and decompiled UnrealScript is a reconstruction, not the original source files. The GitHub description also mentions .uasset, but the README’s compatibility table covers only Unreal Engine 1–3 games.

## Primary sources

1. <https://github.com/EliotVU/Unreal-Library/blob/8236c39b79e30887a487ecf9b018204e430a5ebc/README.md>
2. <https://github.com/EliotVU/Unreal-Library/blob/8236c39b79e30887a487ecf9b018204e430a5ebc/LICENSE>
3. <https://github.com/EliotVU/Unreal-Library/blob/8236c39b79e30887a487ecf9b018204e430a5ebc/Directory.Build.props>
4. <https://github.com/EliotVU/Unreal-Library/blob/8236c39b79e30887a487ecf9b018204e430a5ebc/version.json>
5. <https://github.com/EliotVU/Unreal-Library/blob/8236c39b79e30887a487ecf9b018204e430a5ebc/Test/Eliot.UELib.Test.csproj>
6. <https://github.com/EliotVU/Unreal-Library/blob/8236c39b79e30887a487ecf9b018204e430a5ebc/Test/Packages.resx>
7. <https://github.com/EliotVU/Unreal-Library/tree/8236c39b79e30887a487ecf9b018204e430a5ebc/Test/upk>
8. <https://github.com/EliotVU/Unreal-Library/blob/8236c39b79e30887a487ecf9b018204e430a5ebc/CLI/Program.cs>
9. <https://github.com/EliotVU/Unreal-Library/releases/tag/1.12.0>
10. <https://www.nuget.org/packages/Eliot.UELib/1.13.7>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.