Jagged Alliance 2, running in your browser

If you own Jagged Alliance 2, you can now play it in a browser. Point ja2.virtastic.app at the folder your copy already lives in and it runs: the full campaign, full tactical combat, mouse and keyboard, sound intact. Nothing to install, and your game files never leave your machine.

What it’s built on

This is Stracciatella, the open-source reimplementation of the Jagged Alliance 2 engine. The same relationship as our Morrowind port to OpenMW: a community project already rebuilt the engine from scratch, and our job was getting that engine to run in a browser instead of on a desktop. Full credit to the Stracciatella team. We recompiled their engine to WebAssembly; the engine itself is theirs.

What it took

The shape of the problem was familiar from OpenMW: an engine written for a desktop event loop, a desktop filesystem, and desktop audio, none of which a browser gives you for free. Sound became Web Audio. The UI and mouse-driven tactical combat run exactly as they do on desktop, translated onto browser input events. And like OpenMW, it’s a “bring your own data” port: Jagged Alliance 2’s game data is commercial, so the launcher points at your own legally-owned copy and reads it straight off disk. Nothing is uploaded anywhere.

One detail worth calling out: it keeps running in a background tab. Browsers throttle inactive tabs hard, which is normally the right call, and normally invisible unless your game depends on a turn timer or an AI that needs to keep thinking while you’ve alt-tabbed away. Jagged Alliance 2 does. The port accounts for that, so switching tabs mid-mission doesn’t leave the game stuck or desynced when you come back.

Try it

Play it in your browser if you own the game, read the source on GitHub, and if you hit a bug, tell us or drop it in the Discord.

This is our second full release after OpenMW. More are on the way.