Tom Preston-Werner is one of the founders of Github.com. He's a Ruby programmer who has successfully launched a business used by hundreds of thousands of programmers all over the world to host their programming projects. He is also the original developer behind Gravatar.
We also discussed open source software, contributing, hiring developers, and what makes Github such a great place to work. If you want some good pointers about how things should work at a development shop, I recommend this episode.