Thomas Fuchs
Thomas Fuchs has been writing hard-core JavaScript since waaaaay back in the late 1990s.
His famous script.aculo.us framework was created during the development of one of the most highly interactive applications the Web had ever seen. He's continued to push the boundaries of what is possible with JavaScript, with Scriptaculous and its successor, Scripty2.
Script.aculo.us has gone on to be used in such web sites & applications as CNN.com, NASA.gov, Me.com and more.
In addition to being a Prototype core member and Rails core alumnus, Thomas is one of the world's top JavaScript and rich web app performance experts. He is also the author of Textorize, an automated tool that brings beautifully anti-aliased image text to the web (and beats the pants off Photoshop).
He is a self-described "artsy wanker."