Main claim to fame: Creator of Emacs, GCC
Credentials: Founded the GNU Project and created many of its core tools, such as Emacs, GCC, GDB, and GNU Make. Also founded the Free Software Foundation. Winner of the ACM's Grace Murray Hopper Award in 1990 and the EFF's Pioneer Award in 1998.
Quotes: “... there was the time when he single-handedly outcoded several of the best Lisp hackers around, in the Symbolics vs LMI fight.” Srinivasan Krishnan
“Through his amazing mastery of programming and force of will, he created a whole sub-culture in programming and computers.” Dan Dunay
“I might disagree on many things with the great man, but he is still one of the most important programmers, alive or dead” Marko Poutiainen
“Try to imagine Linux without the prior work on the GNu project. Stallman's the bomb, yo.” John Burnette