Commentari is a Disqus like commenting system written in Java/Spring. It was inspired by Phil Leggetter of Pusher.com's Real Time Commenting System
You will need to install the treapdb jar in your Maven repository. Look in the top level jars directory for install.sh which installs this jar and dependency.
Development is done in Spring STS/Eclipse
To Do i. Real time commenting ii. Caching using ehcache iii. Redirect new comments to last page iv. Set max number of comments, currently hardcoded as 99,999 v. Threading - probably needs an embedded Lucene