Alfresco is an open source, open-standards content repository built by the most experienced content management team that includes the co-founder of Documentum.
The Pentaho BI Project provides enterprise-class reporting, analysis, dashboard, data mining and workflow capabilities that help organizations operate more efficiently and effectively.
GroundWork's open source IT infrastructure monitoring solution delivers enterprise-class availability and performance for a fraction of the cost of commercial alternatives.
Pivot is a web-based tool to help you maintain dynamic sites, like weblogs or online journals. Pivot is released under the GPL so it is completely free to use. It is written in PHP, and does not require additional libraries or databases to function.
The Yahoo! User Interface Library is a set of utilities and controls, in JavaScript, for building richly interactive web applications using techniques such as DOM scripting, DHTML and AJAX. The YUI Library also includes several core CSS resources.