The answer, as best I understand it is no. And yes.
No, you may not run a complete copy of the Planeshift game known as Crystal Blue. This would violate the license.
You can download the source from CVS, which includes the server. So long as you\'re talented enough to compile it, you\'ll have the software at your disposal. What you will
not have is any art, textures, music, models, et al. You would have to create all of your own unique artwork and stuff. Essentially create your own MMORPG. Better have Milkshape 3D, Blender, or 3DS Max handy. You\'ll prolly need good knowledge of SQL, and be prepared to tinker with some PHP.
So... you have to be willing to create your own game from scratch, with the exception of the software.