sentences:  Their game "Quake" was ported to Linux in 1996, once again by Dave D. Taylor working in his free time.Later id products continued to be ported by David Kirsch and Timothee Besset, a practice that continued until the studio's acquisition by ZeniMax Media in 2009.In 1991 DUX Software contracted Don Hopkins to port "SimCity" to Unix, which he later ported to Linux and eventually released as open source for the OLPC XO Laptop.