QuakeC

QuakeC is a programming language based on  C, which is used by Quake and its various mods. Similarly to  Java, QuakeC code isn't compiled into native machine code, but instead is compiled into a file called progs.dat, which is interpreted into native code at runtime via a  virtual machine built into the game engine. This allows the same mods to work across multiple platforms, regardless of operating system and architecture.

Quake II dropped QuakeC in favor of native DLLs (written in regular C), and GoldSrc upgraded most of the codebase to  C++. Despite this, remnants remain, with the model code having been reworked into the QC files used by the GoldSrc and Source versions of StudioMDL.

External links

•  QuakeC on Wikipedia
• quake-rerelease-qc - QuakeC source code for the progs.dat files used by the 2021 Quake remaster.