Quake 1996 open-source mods

Mods that include the original code, thus allowing the player to either tinker with the code or even add it to their own customized PROGS.DAT for use in their own modifications. The difficulty of adding it may vary; this simply categorizes those that have the possibility of doing such.

Note that some modifications may have multiple versions. Early test versions are often closed-source before eventually moving to an open-source release. The most recent version takes priority in such a case.