Apache Jackrabbit uses [Subversion|http://subversion.tigris.org/] to manage source code. See the [Subversion book|http://svnbook.red-bean.com/] and the Apache [instructions|http://www.apache.org/dev/version-control.html] for using Subversion.

The Jackrabbit source code is available at http://svn.apache.org/repos/asf/jackrabbit/ and can also be browsed using the [ViewVC|http://viewvc.tigris.org/] interface at http://svn.apache.org/viewvc/jackrabbit/.