Drupal is an open-source platform and content management system for building dynamic web sites offering a broad range of features and services including user administration, publishing workflow, discussion capabilities, news aggregation, metadata functionalities using controlled vocabularies and XML publishing for content sharing purposes. Equipped with a powerful blend of features and configurability, Drupal can support a diverse range of web projects ranging from personal weblogs to large community-driven sites.

Textile takes plain text with *simple* markup and produces valid XHTML. It's used in web applications, content management systems, blogging software and online forums.

WikyBlog is a collaboration software that fuses the collaborative editing features of wikis with the user friendly publishing characteristics of blogs.

Textpattern is a flexible, elegant and easy-to-use content management system. It is both free and open source.

Project Steve Guttenberg allows you to create an online journal or "blog" with a minimum amount of hassle. PSG doesn't take control of your website. It doesn't have a massive list of dependencies, such as a database server.

A blog software which resides on your webserver. Includes multiple blog capabilities and RSS syndication.

LifeType is an open-source blogging platform with support for multiple blogs and users in a single installation.

FlatPress is an open-source standard-compliant multi-lingual extensible blogging engine which does not require a DataBase Management System to work.

b2evolution includes all the features of traditional blog tools, and extends them with evolved features such as file & photo management, advanced skinning, multiple blogs support as well as detailed user permissions...