What public domain thesauruses are available? [duplicate]

Possible Duplicate:
English synonym online database?

I am working on a project which needs access to the database of a English synonyms, preferably as a raw text file. Are there any public domain, open source, or similarly licensed thesauruses which have a downloadable database and in a simple syntax.

How about OpenThesaurus?

OpenThesaurus is a PHP/MySQL-based web interface that lets people collaboratively work on a thesaurus. The thesaurus can be exported in many formats like OpenOffice.org, plain text and KWord.

How can a raw text file be anything other than a word list? For it to be a thesaurus, it would have to be indexed, right?

You could download and install LibreOffice and then add this extension. Both the office suite and the extension are FLOSS (free/libre open-source software). Note that some users are reporting problems with the extension and at the moment it appears that only US English actually works.