Well, I searched the forum and I didn't find anything interesting, because I Just want Vanilla sync the users data with Joomla!. I don't want any Joomla! component or anything else.
And I want to know how is possible to translate Vanilla. I've looked at the source files and I didn't find anything interesting.
I would imagine that Single Sign-On, that currently only works with Wordpress, could be made to work with Joomla as well. I wouldn't know how to do it however...
@scorchpt - Yes, absolutely. You can take a look at the wordpress plugin (included in the sso download) to see how I made it all work. There are also generic instructions here: http://vanillaforums.org/page/SingleSignOn