If you are good at programming CMUD and are running vista, it's very good. I tried to switch from ZMUD to CMUD and it was too quirky for me. I like ZMUD better for simplistics.

They sometimes package them together for the same price, but they are both very good in my opinion.

The reason I say if you are good at programming, the guy who played Oscerald had some very cool scripts for things like highlight his opponents damage different colors and stuff, that I just haven't gotten to work on zmud.

Other than that they are virtually the same. CMUD is supposed to be better and for vista, but it can be more difficult I think.