The upcoming maintenance release of Fedora 2.2.4 replaces the aging Kowari triplestore with Mulgara.
Earlier last week, I committed the Mulgara-related updates to the maintenance-2.2 branch (r7733). Pending the backport of the fix for FCREPO-239, we should be ready for release.
The replacement of Kowari 1.0.5 with Mulgara 2.0.5 (the current stable release at this writing) brings a number of bug fixes, performance and stability improvements, and new features. A full list of modifications since the Kowari fork is available in the Mulgara distribution in the directory KOWARI-MODIFICATIONS.
Notably, with this update, the Resource Index search interface (risearch) no longer supports RDQL. However, TQL continues to be supported and SPARQL support has been introduced.