Overview
The QuakeC source to the original id Software Quake game logic was published in 1996 and used as the basis for modifications like capture the flag and others. QuakeC source code is compiled using a tool called qcc into a bytecode kept in a file called progs.dat. The programmers of Quake modifications could then publish their progs.dat bytecode without revealing their source code. Most Quake mods were published this way.
QuakeC allowed the Quake engine to dominate the direction of the first-person shooter genre. Thanks to Carmack's idea of extending video game life by adding unlimited expandability (extensibility already played a big role in Doom), an enormous Internet community of gamers and programmers alike has arisen and many modern multiplayer games are extensible in some form.
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