S&box
s&box is a modern game engine, built on Valve's Source 2
...Built on a cutting-edge game engine, s&box allows creators to prototype, build, and share interactive game modes, tools, and environments using C#, JavaScript, and visual scripting, promoting accessible content creation for developers of varying skill levels. The platform emphasizes multiplayer and community experiences, giving creators direct control over networking, physics, rendering, and audio without needing to build those systems from scratch. With real-time recompilation and fast iteration loops, developers can see changes instantly, speeding up the creative process dramatically compared to traditional engines. The sbox ecosystem fosters collaboration, sharing, and extension through packages and community content, enabling a vibrant marketplace of user-created mods and assets.