Lokka is a blogging/CMS tool for the personal cloud.
Users who are accustomed to WordPress or other existing systems like it will find it easy to manage.
It's easy on theme designers, and provides a clean plugin API for Ruby developers.
Lokka runs not only on Windows, Mac OSX, and UNIX variants, but also in cloud environments like Heroku, Sqale and Amazon EC2. You can operate a practical website for free.