Microsoft has a clever Home Use Program that "provides a simple way for staff to work at home with the same Microsoft products they use at work." It's also a great way for Microsoft to spread its software and prevent would-be Mac or open-source users from straying from the Microsoft fold.
Speaking of which, Apple has a similar program, of which my company takes part. I can get Apple hardware and software at a discount, even when not buying it for work. To Apple (and Microsoft), it's a way to expand adoption at a lower cost of sale.
To these efforts, however, we should add a third "Home Use Program." It's called Sourceforge.net. At Sourceforge.net you can download popular open-source projects at work...for free. You can then head home to buy these exact same programs...for free!
It's the ultimate Home Use Program. Completely free. What a bargain!