What is Apache Jackrabbit?
Apache Jackrabbit is a fully featured content repository that implements the entire JCR API. The Jackrabbit project was started when Day Software, the JSR-170 specification lead, licensed their initial implementation of the JCR reference implementation. The Jackrabbit codebase was used for the official reference implementation (RI) and technology compatibility kit (TCK) released along with the final JCR API.