Typo
Typo has been around since March of 2005 making it one of the oldest blogging platforms in Rails. It provides every feature a modern blogging engine needs: powerful themes, extensions, smart users management, SEO capabilities and brings a great user experience for both site visitors and Web developpers. Typo is easy to install and even easier to use. Typo is free software released under the MIT licence and maintained by a bunch of cool people on their spare time. The current version is Typo 6.1.0 for Ruby on Rails 3.0.10.