From the webpage:
VocBench is a web-based, multilingual, vocabulary editing and workflow tool developed by FAO. It transforms thesauri, authority lists and glossaries into SKOS/RDF concept schemes for use in a linked data environment. VocBench provides tools and functionalities that facilitate the collaborative editing of multilingual terminology and semantic concept information. It further includes administration and group management features as well as built in workflows for maintenance, validation and quality assurance of the data pool.
Current release is (1.3) but 2.0 is due out “Autumn 2012” as open source GPL license.
Another tool that will be of interest to topic map authors.