Early versions of Quake were created on NeXTSTEP too.

This picture was taken near the end of Quake 1's development period in 1996. American is sitting at his desk, checking out my map E2M1 (with the original Quake interface for the Base theme, in fact). The computer he's using is a NEXTSTEP system made by HP (nicknamed the Gecko), in fact the machine name of his computer was "idtokay". Under his desk, the black hardware looks to be an older NeXT Computer. The room we were working in at that time was called the War Room -- we were all working in the same room while the rest of the office was being built out. To the right of American's desk was Tim Willits', and then my desk.