TeX is a sophisticated typesetting system that has been in widespread use since approximately 1980. TeX's originator, Donald Knuth, structured the system so users could add functionality. The TeX Users Group (TUG) was founded in 1980 "for educational and scientific purposes, to provide an organization for those who have an interest in typography and font design, and are users of the TeX typesetting system." This book contains interviews with about 50 people who have been or are active users or developers of TeX and its variations or active in TUG or one of the many local TeX user groups. As such, the book provides something of a history of the evolution of TeX and profiles of the people instrumental in this evolution.