OpenOffice Search is a document indexer and search engine for OpenOffice documents. It is Java-based, so it will run on any J2SE enabled platform and uses an embedded Derby (Cloudscape) database.
Trinity is an XML-based information engine that liberates data, view and function from each other - making each more flexible and powerful. It uses WebDAV to access XML data, and comes with both a GUI environment and an Apache based web interface.