openage

Last reviewed Aug 26, 2026 · 798 words

openage is not something you install to play Age of Empires II tonight. After more than a decade of development it is an engine and a toolchain, not a finished game: you can build it, convert the original game's assets, and watch units walk around a map, but matches, campaigns and multiplayer are still in progress. That is the honest state of a 14,398-star project, and it is stated plainly so you can decide whether you are its audience. Its audience is modders, engine programmers and people who want the AoE II asset formats documented and readable, and for them it is remarkable.

What it actually is: a C++ engine with Python glue and a data language

The catalogue lists Python, which is the visible surface; the core is C++ with Python (via Cython) driving the build, the asset converter and scripting. The third piece is nyan, a purpose-built data description language the project created to express units, techs and civilisations as inheritable objects rather than the binary tables the original game used. The point of that design is modding: a mod becomes a set of nyan files that override or extend the base game's data, with the engine none the wiser.

Cross-platform means Linux, macOS and Windows, built from source with CMake. There are no packages in the catalogue's deployment list beyond "bare-metal" and "source", and that is accurate; expect to install a compiler toolchain, Qt, OpenGL headers and a handful of libraries, then wait on a long build. On a 4-core laptop the first build is a coffee break, not a click.

You need the original game assets, legally

openage ships no art, sound or maps. It reads them from a copy of Age of Empires II you own: the original CD release, HD Edition or Definitive Edition from Steam all work with the converter, which extracts sprites, terrains and sounds into openage's own formats on first run. This is the same arrangement as OpenTTD before it got free graphics, or OpenRA with the original Command & Conquer files, and it keeps the project on the right side of Microsoft's intellectual property. The Definitive Edition path is the one most people take now, since that is the version on sale.

The 1,024 MB RAM figure is for the running engine and the conversion; the converted asset directory itself will want a few GB of disk depending on which edition you feed it.

How a self-hoster fits this into a stack: mostly, you do not

openage is a desktop project. There is no server binary, no Docker image worth running, nothing to put behind a reverse proxy. Where it belongs on a self-hosting site is as a modding and preservation tool: if you maintain an AoE II community, the converter and nyan data are the cleanest way to read and document the game's rules, and the engine is the only open codebase where you can trace how pathfinding or the tech tree is meant to work. A game server for the community is a different question, and for the retail game it is answered by the publisher's lobby, not by anything you can self-host.

Two things it is not. It is not WololoKingdoms, the older tool that converted Definitive Edition civilisations into the HD Edition, despite the resemblance in the catalogue's naming. And it is not a drop-in like ScummVM, where a working game appears once you point it at data files.

What to play instead while you wait

If the goal is an open-source real-time strategy game you can install and play this evening, 0 A.D. is the answer: a complete, free game with its own assets, GPL code and a working multiplayer lobby. If the goal is AoE II specifically, the Definitive Edition with its own lobby is still the only finished way to play, and openage stays a project you follow on GitHub. The game engines category lists the other reimplementations, several of which (OpenRA, OpenTTD, Julius) are at the playable stage that openage is still working toward.

What I'd do

Modder or engine-curious programmer: clone it, build it on Linux (the smoothest platform), run the converter against a Definitive Edition install, and spend an evening reading the nyan files, which is the best documentation of AoE II's data model that exists outside Microsoft. Anyone hoping for a free AoE II: install 0 A.D. tonight, star openage, and check back yearly. Do not spend a weekend on the build expecting a game at the end; the project itself tells you it is not there yet, and I would rather you heard it here first.