What is it?

Blogentis is a blog publishing platform written in Java. It supports multiple blogs with multiple authors each, sections, RSS feeds, trackbacks and pingbacks, comments and a plugin system.

Can I use it?

The code is pretty much alpha-quality right now, as several important pieces are missing, namely that you cannot add blogs or users from the web - you have to use SQL commands. Other than that (and the sparse documentation), it is quite stable and working.