Idealware is providing online a report on open source content management systems by comparing Wordpress, Joomla!, Drupal, and Plone. This 60-page independent Idealware report in PDF format provides both an introduction to the topic and a very detailed comparison of the four systems. The report also includes their new directory of the consultants and firms who help nonprofit create websites and implement these Content Management Systems.
The analysis in this report is excellent and provides my favorite type of comparison between content management systems, fair and balanced. The report doesn't try to rank for you which open source CMS is number one but instead intends to provide you the information you need to determine which CMS is best for you and your project.
This guide even has a small section giving other CMS options besides the four mentioned open source content management systems. If you're a mid-sized to large organization that prefers propriety software over open source software, the report even makes a small mention of well known CMS such as Hot Banana, Ektron, CommonSpot and Sitecore. This report clearly shows that the authors understand the type of analysis needed for site owners to pick the best CMS for their organization. This report is current and does not rely on past perceptions of a particular CMS.
The Idealware report comparing WordPress, Joomla, Drupal, and Plone is available for a free download after providing some basic registration information.