Joomla was the result of a fork of Mambo on August 17, 2005. At that time, the Mambo name was a trademark of Miro International Pvt. Ltd, who formed a non-profit foundation with the stated purpose of funding the project and protecting it from lawsuits. The Joomla! development team claimed that many of the provisions of the foundation structure violated previous agreements made by the elected Mambo Steering Committee, lacked the necessary consultation with key stakeholders and included provisions that violated core open source values.
Joomla! Developers created a website called OpenSourceMatters.org (OSM) to distribute information to the software community. Project leader Andrew Eddie wrote a letter that appeared on the announcements section of the public forum at mamboserver.com. Over one thousand people joined OpenSourceMatters.org within a day, most posting words of encouragement and support. The website received the Slashdot effect as a result. Miro CEO Peter Lamont responded publicly to the development team in an article titled “The Mambo Open Source Controversy — 20 Questions With Miro”. This event created controversy within the free software community about the definition of open source. Forums of other open-source projects were active with postings about the actions of both sides.