Malaga-tsearch is a tsearch dictionary implementation using a natural language development environment called Malaga for parsing words. It's currently been developed with the Finnish Malaga implementation, but grammars for other languages could be used.
The Malaga-tsearchproject is a PostgreSQL Community project that is a part of the pgFoundry.
The pgFoundry page for the project is at http://pgfoundry.org/projects/malaga-tsearch, where you can find downloads, documentation, bug reports, mailing lists, and a whole lot more.