MS Windows Server 2003 and xna Game Studio are also free. Yes, really and truly, Microsoft is giving away the full versions of all that software for zero cost.
Just one catch. You have to be a student in order to get it. Still, that sounds like a pretty good deal to me. No longer will cash-strapped students be faced with a choice of Eclipse or Eclipse. Read more on the Microsoft DreamSpark (Channel 8) site then (if you qualify), get ready to download.