Another feature that I find myself always wanting is a "kill script" button and/or command. This comes in handy when I am testing a new python script and, accidentally, throw in an infinite loop. It would be nice to have some sort of kill switch not only for python scripts but even for something as simple as ray-tracing. There are times when I am ray-tracing a complicated scene and realize that half-way through the ray-tracing process that something was missing. In that case, I normally have to kill PyMOL and start all over again (and hopefully, I'll have the scene/session saved). Having this function would greatly enhance my productivity.