Squirrel
Lightweight scripting language designed for embedding in games — used in Left 4 Dead, Portal 2, and Source engine games.
dynamic
interpreted
since 2003
oopscriptingimperative
Squirrel was designed as a scripting layer for the Source game engine at Valve and is used in Left 4 Dead, Portal 2, and Dota 2 for game logic, AI, and level scripting. Its C-like syntax, class system, and generator support make it approachable for game designers. It is also used in vehicle firmware (Tesla) and IoT scripting environments.