Saxman
From Sonic Retro
Saxman wrote the first Sonic hacking guides, which inspired LocalH to write his Sonic 2 Beta hacking guide. He is also a damn good musician, especially if you like Huey Lewis and the News. Unfortunately he has left the Sonic community.
He has, however, not given up on engineering and hacking, and is working on a revolutionary new engine called simply "ProSonic". Details can be found at Saxman's Blogger page.