Aspect-Oriented Windowing (AOW)
I'd like to coin a new term for what AutoHotKey does: Aspect Oriented Windowing (AOW). Basically AutoHotKey lets you hook into various Windows "events" and modify them on the fly--all with a high-level scripting language (or you can use the macro recorder to record your mouse and keyboard actions, thus avoiding much of the coding).
It's a bit like Aspect-Oriented Programming in that you can take an event (a keypress or the opening of a window with a certain title) and do something after or instead of the event (mapping to a different key, etc.)
It's pretty neat (and fun) actually. Linux users have always enjoyed being able to modify the OS to fit their needs--now Windows users can too, and on the GUI level which is often easier.