I have been using Doom source ports since around 2002, starting out with ZDoom 1.22 before discovering Doom Connector and largely playing with Doom Legacy co-op. It's been a long crazy journey, using JDoom (now Doomsday Engine), ZDoom 2.0+, ZDoomGL, boom, prboom, glboom, pr/glboom+, Eternity, Vavoom, Risen3D, Skulltag, Zandronum, ZDaemon... there's just so many.