When the source code to Quake was leaked and circulated among the Quake community underground in 1996, a programmer unaffiliated with id Software used it to port Quake to Linux, and subsequently sent the patches to Carmack. Instead of pursuing legal action, id Software, at Carmack’s behest, used the patches as the foundation for a company-sanctioned Linux port. id Software has since publicly released the source code to Quake, Quake 2 and most recently Quake 3, all under the GNU General Public License (GPL).
