Lotb, a GPL multiblog system
Lord of the Blogs (Lotb) is a tool for managing several weblogs from a unique site. The weblogs can be in different sites and can use different databases and different software.
The project was born at 2006 by the hand of Javier Sancho, in an intent to create a farm of blogs using only free software.
Lotb is free software. It's distributed under GNU/GPL license. Licensing terms can be found at the License section. Original copy of the license can be found at the official GNU site. Now, Lotb uses GPL version 2 but in the near future will use version 3.
Lotb is written in PHP and uses SSL-certificates and signed messages in the communications between blogs and Lotb. Additionally, the project team is developing plugins for different types of blogs, like Wordpress and Textpattern, to permit that communication.