The static Jackrabbit web site at http://jackrabbit.apache.org/ is managed using svnpubsub as outlined in the ASF's guide for project websites. More dynamic parts of the site, like active documentation and various guides (including this page), are kept in the wiki where all registered contributors can more easily modify them.
The static site sources are kept in https://svn.apache.org/repos/asf/jackrabbit/site/live/ and can be directly modified by all Jackrabbit committers. The svnpubsub mechanism makes any changes visible on the public web site within seconds of the respective commits. Other contributors can submit patches against the site sources through the JCRSITE issue tracker.
Note that the current site sources are based on a raw HTML export from the Confluence wiki we used earlier for managing the project web site (until Apache infra discontinued the service), so modifying them can be a bit tricky. Instead of the root of the site tree (as one might guess from the URLs) the exported HTML pages are stored in the JCR subdirectory, and a few rewrite rules in the .htaccess file are used to map them to a cleaner URL space. These contortions should eventually get phased out as we complete the migration away from Confluence.