Hacker News Reader

Vagrant's online documentation is done with Jekyll, the idea being that it's very easy for contributors to edit content and view their changes.

Blogofile (Python) is basically awful, but it's great once you spend a few days fixing the kinks and make it work.

Make sure you don't get the latest version from GitHub, but easy_install it and build from simple_blog.

Have a look at ikiwiki. I use it to generate a blog on github, but as a wiki it's great for notes as well.