The Quake2World source code is licensed under the GNU General Public License Version 2.0. For artwork and media, we accept work released under the GPL, Zlib, MIT, WTFPL, all CC variations, and generally anything that allows us to freely distribute the game.
We are aware that following the DFCW or DFSG would allow Quake2World to be included in free operating systems distribution. However, being completely "free as in freedom" is less important to us than providing a great game and giving our contributors the freedom to make their own licensing choices.