Jonathan Coulton is a former computer programmer and current musical geek genius. He's a Yale graduate and has contributed theme songs to several TV shows, including Code Monkeys and Mystery Diagnosis. Coulton is most famous for penning the extremely popular song, "Still Alive", played over the end credits of Portal. Coulton is also the music director for "The Little Gray Books", an intellectual variety series created by "Daily Show" regular John Hodgman. In September of 2005, he started a year-long project called "Thing A Week", where he wrote and recorded 52 musical pieces in an effort to boost his creativity. Coulton licenses his songs under the Creative Commons Attribution-Noncommercial license, which allows people to use his songs for noncommercial projects. As a result, his songs have been used in countless homemade music videos posted to YouTube.
You can get more information about Jonathan Coulton on his blog/website and follow him on Twitter (@jonathancoulton)