This document analyzes the market share and brand strength of 20 open source content management systems (CMS). It measures adoption rates through metrics like downloads, installations, and third party support. WordPress has the highest average weekly downloads at 983,625. Joomla!, Drupal, DotNetNuke, CMSMadeSimple, Liferay, TYPO3, and eZ Publish also have substantial download numbers. The report aims to identify market leaders and trends in the open source CMS industry.