Earlier I talked about how programs like Roboform have adopted an element of the open source business model to sell their proprietary goods.
Spybot is a cool piece of work, if like most Windows users you're bedevilled by advertisers sticking cookies in your system without permission or crooks adding spyware. It matches what your browser has saved to its own database of nasties, then lets you delete some or all. (Save that Amazon cookie -- it's delicious.)
Spybot is closed source, but its free. Here's my favorite bit from the license:
I grant you the license to use Spybot-S&D as much as you like. But if you like it, I ask two things of you: say a prayer for me (and the most wonderful girl while you're at it ;) ) to your god - or whatever you believe - and wish us some luck.
You can buy corporate licenses to Spybot, you can buy Spybot merchandise, you can even donate to Spybot. But you don't get the source code, you can't reverse engineer it, and you're not buying support.
Donations, merchandise, and corporate licenses seem to be enough to keep Spybot operating, and they're not the only folks like this. It says something about the true costs of development that this is possible. But how far down this evolutionary trail can we go before we starve?