The invaluable Mickey has an excellent post up on proced, a ps/top-like utility built into Emacs. If you find yourself using top and ps—and what serious developer doesn’t?—you’ll love having the functionality built right into Emacs. One more reason not to leave the comfort of your editor.
As usual, Mickey explains the functionality in detail so I’ll just send you to him for the full picture. Sadly, if you’re an OS X user, like me, proced won’t work because OS X lacks /proc. It’s doubly insulting that it does work under Windows. If you’re a Linux or Windows user, check out Mickey’s post and enjoy and power. If you’re an OS X user, have a beer and weep into it. I feel your pain.