Someone from the era of short usernames on unix boxes, along with "esr" and "rob". To more directly answer, it's Richard Stallman. Known for the free software movement and emacs among other things.
I totally disagree. I don't agree with anything he believes in outside of software as far as I can tell, but the Cathedral and Bazaar was pivotal. Not only that, but if you've never looked at the source code for Nethack, you should. I admit, I haven't looked at it since he was leading the project, but it remains in my mind as one of the best pieces of C code I've ever played with. Also, his description of working with Fetchmail revolutionised (at least for me) the idea of just taking some code that someone else has abandoned and slowly improving it.
He never understood software freedom, but as far as I can tell he is responsible for communicating the way that free (as in freedom) software can be competitive in the real world. Before that, all anyone would talk about was how we had to have free software for moral reasons (which I personally believe). He was the one that saw how successful projects were being run, put 2 and 2 together and told everybody else how to do it. I have much respect for ESR and I wish that the good things he has done had a wider audience.
Unlike in fiction, real-life humans aren't universally perfect to everyone's standards. In some areas they believe or practice something great, in others they say or do repugnant stuff. Fortunately, you can evaluate one's contribution in different areas in isolation, and I wish more people would learn how to do that.
What has he done, besides The Cathedral and the Bazaar...?
Most of his open source contributions seem to be littering up source files with long-winded comments and grandiose attributions to himself. I've read a fair bit of his code and it's certainly not impressive. Quite the opposite actually.
I'm further right on the political spectrum than ESR is. It's his delusions of grandeur and constant, smug championing of his own relevance that I can't stand...
