1.TorqueGameEngines / Torque2DA completely free, open-source, 2D game engine built on proven torque technology.CMIT1.7K total140 forks+164 starsfrom 1,556 · score 5.11
2.ioquake / ioq3The ioquake3 community effort to continue supporting/developing id's Quake III Arenafpsfps-gamefps-enginegamegame-developmentgame-engine+4 moreCGPL-2.02.9K total629 forks+148 starsfrom 2,715 · score 5.00
3.amzeratul / halleyA lightweight game engine written in modern C++CAPACHE-2.03.9K total180 forks+72 starsfrom 3,799 · score 4.29