VScript, introduced in Left 4 Dead 2, is a virtual machine for scripting that acts as an abstract binding layer between the Source engine and external scripts. According to the Alien Swarm SDK, the following scripting languages are, or could be supported in the near future:
Script files are read from
/scripts/vscripts/ inside the game directory.
- Team Fortress 2
- Only exists on the SFM build of the game. No TF2 or SFM specific API. Unused.
- Portal 2 (Client/UI only)
Main article Vscript Fundamentals