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New version out, now with fighters and carriers. http://freeorion.org/index.php/Main_Page The game is totally playable nowadays and I read it works fine for multi-player too.
Someone should get this version into Ubuntu's repository to replace the version in there from 2013 (0.4.3)
Version is out. This fixes some problems with 0.4.7. Works on Linux, Windows and OSX.