# OpenApoc

> OpenApoc is an open-source re-implementation of X-COM: Apocalypse for Windows, written in C++ with SDL2, playable with your own copy of the game and fully moddable.

Web page: https://emulationking.com/microsoft/windows/games/xcomapocalypse/ports/openapoc/
Page updated: 2026-10-26

- Developer: OpenApoc Team
- Port type: Reimplementation (The game was rebuilt in new code that plays like the original and loads its data from your own copy.)
- Game: [X-COM: Apocalypse](https://emulationking.com/microsoft/windows/games/xcomapocalypse/index.md)
- AI use: Not stated
- Source code: https://github.com/OpenApoc/OpenApoc
- Runs on: Windows

What you need: The original X-COM: Apocalypse CD image (`cd.iso`), or the game files from GOG or Steam set up as the project's guide describes.

OpenApoc is an open-source re-implementation of X-COM: Apocalypse, Mythos Games' 1997 strategy game, started by PmProg in 2014. It needs the original game's files and is written in C++ with SDL2. Julian Gollop, the designer of the original X-COM games, has said he supports the project.

It aims to recreate the game's city view and tactical battles while making almost everything moddable, from balance to new content, and its saves are human-readable XML in a zip archive. Its builds are published as pre-releases while work continues.

## How to set it up

1. Download the Windows installer or zip and install or unpack it.
2. Copy your X-COM: Apocalypse CD image into the `data` folder as `cd.iso`, or follow the project's setup guide for the GOG or Steam release.
3. Run `OpenApoc` (or its launcher). The builds here are the project's pre-release builds.

## Latest builds

Download these from the web page: https://emulationking.com/microsoft/windows/games/xcomapocalypse/ports/openapoc/#download

- Installer for Windows: 20260916 (2026-09-16)
- for Windows (x64): 20260916 (2026-09-16)