BlogsWeek.com

Typo is a blog engine built using Ruby on Rails, a well known web application platform. It was written in early 2005 by Tobias Lütke, a German programmer also creator of the popular Shopify e-commerce platform, and is currently developed by Piers Cawley and Frédéric de Villamil.

Typo features include:

* Textile, Markdown and SmartyPants support
* Ping / Trackback
* Categories / Tags
* Ta-da Lists, del.icio.us, Flickr, 43 Things, and Upcoming syndication
* Ajax based live search and commenting
* Ajax based comment moderation
* Full text search with live preview
* RSS2 and Atom feeds as well as feeds for comments and trackbacks
* Comment feeds
* Caching - Typo only creates the XML files when needed and serves static copies to your readers
* Supported databases: MySQL, SQLite, and PostgreSQL
* Easy to type permalinks
* Web based administration and posting interface
* Migration scripts from many platforms as well as plain RSS

Typo is released under a Creative Commons License.