Roller

Apache Roller is a full-featured, multi-user and group-blog server suitable for blog sites large and small. Roller is a Java web application that should be able to run on any Java EE server and any relational database. Its features include:

• Multi-user blogging: can support tens of thousands of users and blogs
• Group blogging with three permisson levels (editor, author and limited)
• Support for comment moderation and comment spam prevention measures
• Bloggers have complete control over blog layout/style via templates
• Built-in search engine indexes weblog entry content
• Pluggable cache and rendering system
• Support for blog clients that support MetaWeblog API
• All blogs have entry and comment feeds in both RSS 2.0 and Atom 1.0 formats