Editor: ResurrXtion is a small application that takes the place of the feature in MacOS 9 that allowed you to tell your Mac when to boot from sleep or a complete shutdown. I used to like having my Mac awake and ready when I got home every day from work, and I really miss this under MacOS X.
How is it done?
Well, I'm not going to go into the details, but essentially there's a piece of hardware on certain Macs that has a counter in it. After this counter is set, it decrements down in real time. When it reaches 0, the Mac boots or wakes from sleep. This API call used to function in the Power Manager API, but if you check out the Carbon documentation, this call does nothing under OS X. I dug Up some old hardware documentation recently, fiddled with it, and found out exactly what to do.