Well, the thing is that the emus on the XBOX run on .xbe, which is the windows equivalent of .exe. The XBOX however will not run exe files so you are stuck on whatever port comes out for a certain system. As far as I know PCSXBox is the only playstation port available for the XBOX. And they have ceased development and support from what it looks like.
Also, it will only emulate PSX games. So no PC ports im afraid.