OSQA is a free, entry-level Q&A system from the makers of AnswerHub, the market-leading professional Q&A platform. Looking for Enterprise functionality? Checkout http://answerhub.com
jMimeMagic is a Java library for determining the MIME type of files or streams.
Java implementation of the Hipchat API - customized to allow custom hostname
A library for using Memcached as a second level distributed cache in Hibernate.
Cloud Foundry buildpack for running Java applications using Java 7 and Tomcat 7
Spring Social SalesForce API
An example plugin to use as the foundation for building your own AnswerHub plugins.
Spring Social extension with connection support and an API binding for Google
A full version of bootstrap with a layer of enhancements. If you're a journalist, contact email@example.com for an early download of the beta. Details on v.1 release here: http://adamkochanowicz.com/2012/twitter-bootstrap-like-youve-never-seen-it-before/