The Languages of the Stars:
Constructed Languages in Fact, and Science Fiction
Universal Translator Assistant using the technology of today to bring the theories of yesterday to the languages of tomorrow
Important: What is Wrong with this? - why UTA isn't a translator
Java based Galactic Dictionary - run it in your browser!
Here is the current (based on the Institute of Ra'tleihfi Department of Xenosociologylexicon) Romulan Dictionary - now available for download: PC and open source versions. This dictionary is based on a variety of sources, including Diane Duane's novels.