http://ifh.firstones.com/index.shtml

Been reading rave reviews of this. It's a Babylon5 freeware space simulation, with realistic physics (like b5 had) and capable of supporting huge battles in space.  I'm downloading it now. More after I play a bit.

Check out Starshatter as well.
Its in closed beta at the moment (which im in, and its pretty damn good), but there is a download for the public release on the website.
It isnt as close to the developer version, but its good to see what to expect in the future.

Theres a promising looking B5 mod for Starshatter, but i havent downloaded it yet because its bigger than the game its a mod for  

Babylon.....5......space...sim!!!!!!  :blink:  

/me feutially attempts to hold back the spooge......

Damnit, J Michael Straczynski  might have to give me a restraining order now as well......