Stasis Lang

Stasis is an experimental programming language and toolchain for deterministic, game-style programs. Many of the games on this site, including Gambit Guard and Sheep Herder, are written in it.

The idea

Games and simulations work best when the same inputs always produce the same outputs, state is explicit, and nothing unexpected happens on the hot path. Stasis is built around that:

• Static global memory with no hidden allocations, so there are no garbage collection pauses or surprise allocations during a frame.
• Predictable layouts. Field offsets and array layouts are stable, and structures are lowered to a structure-of-arrays layout for cache-friendly access.
• A simple game loop. main() runs once, then tick() and render() run every frame on a fixed step.
• Determinism. A fixed-step, tick-based model makes replays, debugging, and lockstep multiplayer practical.

Live iteration

The development loop is the part I am proudest of. Stasis compiles to machine code with an in-process JIT, recompiles changed files in the background, and hot-swaps the new code between ticks. Changing a function that few others depend on can update a running game in a dozen or so milliseconds, without a restart. An on_code_swap() hook lets a game fix up its state after a swap.

The compiler was rebuilt in Rust to make that hot swap reliable. The toolchain now targets Windows and Android natively and the web through JavaScript, with WebAssembly mostly working.

Trade-offs

Stasis is experimental and changes quickly, so expect breaking changes. Games must allocate their memory up front. There is no library ecosystem yet. It is a good fit for small, self-contained games and simulations, not yet for shipping large commercial titles.

Licensing

Stasis uses a revenue-threshold commercial license. It is free for internal use and for projects with under $10,000 in annual revenue. Above that, there is a 1% share of gross revenue from products that use it.

Learn more

The Stasis website has the documentation and examples, and the GitHub repository has the source and nightly releases.