If your keyboard supports PS/2, you can use a Soarer's converter to remap keys and that doesn't require any software to be used on the computer. Might not do everything you need, but definitely worth looking into especially if you'll use with multiple computers since the programming is stored in the converter which is resides in the hardware. So say you have a model M, you could remap the ALT key to the Command/Apple key permanently for example even when used on other computers, no software required.
