The Apache Jackrabbit Project has been formed to develop and maintain an
open source implementation of the Content Repository for Java Technology API
(JCR), as specified within the Java Community Process by
<a href="http://www.jcp.org/en/jsr/detail?id=170">JSR 170</a> and
<a href="http://www.jcp.org/en/jsr/detail?id=283">JSR 283</a>.
JCR specifies an API for application developers (and application frameworks)
to use for interaction with modern content repositories -- content management
systems that provide content services such as versioning, transactions,
indexing, etc.