Because Blogojevich would be too tough to remember. It's a pluggable blogging system for Rails 3.

the tiniest blog-engine in Oz.

Add a blog to your Rails application in minutes with this mountable Rails Engine

A really straightforward open source Ruby on Rails blog engine designed for integration with Refinery CMS.

Since Typo has been in existence since March 2005, it is likely the oldest blogging platform in Rails. It has a full set of features you would expect from such an engine, which include powerful SEO capabilities, full themes, and plug-in extensions.

Serious is a simple, file-driven blog engine inspired by toto and driven by sinatra with an emphasis on easy setup

An embeddable file-backed content management system.

PiccoBlog is a simple Ruby on Rails markdown blog engine.