Why is musharraf alive?

The first thing to understand is whatever he done, he done it in the capacity of Chief of Army Staff or President of Pakistan. Their is a reason it's in the constitution, that President can't be prosecuted for his actions.

Bush did a lot of atrocities, even congress members sometime talk about prosecuting him, but this is out of possibility, you can dance, cry or laugh. That's the way it work, ... !