Unity 2.5 for Windows released
This was a MAC OS X only engine, but is now available on the Windows platform
Source and to read the full article, head on over to EDGE-Online
Unity Technologies announced Wednesday the Unity 2.5 game engine, which now is available for use on Windows.
Previously, the engine was only available for Mac OS X. But now the editor is also usable on Windows Vista, XP and 2000, with "100 percent feature parity and interoperability with Mac OS X."