Looking at the source[1] of the blog. It appears to be built with Jekyll[2].
[1]: https://github.com/comoyo/comoyo.github.com
[2]: http://jekyllrb.com/
[1]: https://github.com/comoyo/comoyo.github.com
[2]: http://jekyllrb.com/
All in all we are very happy with Jekyll (and looking forward to development picking up on it now).