From the creators of Garry's Mod, s&box gives you modern C#, powerful Source 2 technology, an intuitive editor, hot reloads in milliseconds and multiplayer built in. Create, playtest and publish without leaving the editor.
Open source. No royalties. No catches.
Everything lives in one window — the scene, the assets, the code and the running game. Lay it out, press play, and keep working while it runs.
Change code while the game is running and see the result in milliseconds.
No waiting on builds. No restarts. No losing your place.
Networking and sessions are part of the engine, not another service to configure.
Pull people straight into a running playtest — no packaging, no sending builds around. Every change you make is networked out live, so everyone already in the session is playing the newest version as you work.
Click publish and your game uploads automatically, ready for people to play instantly.
No installers or addon wrangling. Or export a standalone build and put it on Steam under your own name.
Our Play Fund pays creators out of a shared pot, based on how much people play what they made.
Our code is on GitHub under the MIT license. Read it, change it, and make it work for you.
Build levels with Hammer, then extend it with your own tools, UI, primitives and workflows.
Drag models and materials straight from the asset browser into your scene. Dependencies are available without hunting down downloads first.
Build interactions visually when code would get in the way. Use graphs alongside C#, not as a separate workflow.
Build materials and post-processing effects visually, with live feedback in the editor.
Build PC VR games with the same scenes, components and multiplayer systems as everything else.
Sculpt heightmaps and paint materials straight in the editor. Large outdoor scenes without bolting on a separate tool.
Export your game and release it as a standalone title on Steam.
No royalties. Your game, your name, your revenue.
Get the editor or dig into the docs.
