Weblog software for individuals, educational institutions, and corporations. Free trial available.

A PHP/SQL blogging tool which resides on your webserver. Includes multiple weblog capabilities, and RSS syndication.

Free open-source blog tool. Runs on many different operating systems and uses PHP4 and MySQL.

Open source blogging platform written in object-oriented PHP5. Site includes project news, download links and documentation.

An open-source project for creating a simple CMS for blog authors.

Open source weblog and content management system written in PHP, featuring built-in antispam protection, automated installation and a multilingual interface.

Free collaborative media software for running community web logs . Requires Perl, mod_perl, and MySQL.

Open source microblogging application, aiming to be an alternative to Twitter. Provides a list of existing servers using this software, documentation and information for developers.

Based on an open source project aimed to the development of an "easy to maintain and use" weblog-hosting system. It can host unlimited blogs.

Open Source software for creating Slashdot-style discussion weblogs. Provides links to the software, and help for setting up and running the software.