S&box is coded in C#. Under the hood, it uses the Source 2 engine (CS2, HL:Alyx, DOTA2) and some of its systems: rendering, resources, physics, and audio.
When you create games and addons in s&box, you will be creating them in C#.
We have developed a hotload system which is capable of compiling & hotloading your changes to code within a few milliseconds, which negates the need for a scripting language.
We use a scene system, similar to Godot and Unity. This allows faster iteration, without everything being code-based. The scene system aims to make how everything works more transparent, by being easily visible, and easily accessible.
Our intention is to let you export the things that you make in our engine and release them standalone. We’ll let you do this royalty-free.
Issues and feature suggestions should be posted in the sbox-issues repo.
Please see Reporting Errors.