John Romero was born on 28 October 1967 in Colorado, USA. He started programming games for Apple II and Commodore 64 in 1980. During his career he has been with several companies such as Epyx or Origin but always focusing his titles on the personal computer market. In 1989 he joined Softdisk magazine but, years later, he would leave and found id Software.
John Carmack was born on 20 August 1970 in Shawnee Mission (USA). He has loved programming since his early days in high school. At the age of 14, he tried to steal Apple II computers with the help of his classmates, but they were alerted by the alarm. He was forced to attend a reform school for a whole year where he was described as "a brain with legs". In 1990 John Romero hired him as a developer at Softdisk after seeing his early work. From then on, the duo were unstoppable until 1996, when, with the release of Quake, they parted ways.
After the success of Doom, the ego of the authors was aggravated to the point that the Johns decided to separate their ways after the release of Quake. Both believed that their part of the project was what made it succeed, thus belittling the work of the other. While Carmack believed that everything depended on technique and programming, Romero believed that it was the art direction that made a video game succeed.