Nowadays most Mac-designed keyboards have keys with special functions printed on them (e.g., play/pause, brightness, Dashboard, etc.). In order to use the keys as F1, F2, etc.., the “Function” key must be held down.
This is a nice thought, but I don’t like the “all or nothing” approach. Some of these keys, like volume and brightness, I use all the time. Others I don’t use at all. So for me, it makes much more sense to use FunctionFlip, which let’s a user decide specifically which keys to flip on or off. Once I disabled some of the “picture” keys, I set them up with Keyboard Maestro to have new functionality assigned to them.
Obviously this method isn’t as easy to toggle on or off as Palua, so I suppose it’s a different use case, but I prefer the FunctionFlip method.