Yes, a version of the Thain module has been released to the community. After registering and logging into the site, in the top right hand corner of most pages in these forums you should see a link to 'The Module'. This is a zipped form of the open source version of Thain, compressed in ZIP format (Windows XP and Linux both can decompress the file without a 3rd-party program).
Within the ZIP file you will find a copy of the Thain module, a copy of the Thain Public License, and information regarding Thain's copyright holders. If downloading the module, please take the time to read the licensing and copyright information.
Note: the downloadable version of the module is not necessarily the same version as the live module, and is therefore likely to differ in significant ways from the live module. The open source module version will be updated periodically.