First things first, from John Carmack’s Wikipedia page:
Carmack was the lead programmer of the id video games Commander Keen, Wolfenstein 3D, Doom, Quake, Rage and their sequels. Carmack is best known for his innovations in 3D graphics, such as his Carmack’s Reverse algorithm for shadow volumes. In August 2013, Carmack took the position of CTO at Oculus VR.
Carmack and Kang married on January 1, 2000 and planned a ceremony in Hawaii. Steve Jobs requested that they postpone the ceremony so Carmack could attend the MacWorld Expo on January 5, 2000. Both declined and made a video instead.
Carmack had a rollercoaster of a relationship with Steve. Follow the headline link and just dive in. I found it a fascinating read.