Multiverse show an interesting concept. It’s (supposedly, I signed up for the beta 😉 a complete MMORPG engine, free to use as long as you don’t make money thanks to it. “There are no upfront costs. We only make money when you make money, and if you never charge a cent, you never have to pay us anything.”
%% It’s a philosophy I really like, most software companies should do this since everything has already been cracked! Let us learn your tools easily and we will use them whenever we can to make money and give you what you deserve!

Alias does something like that with their Maya and Motion Builder Personnal Learning Edition. The softs are hardly crippled, just enough so that you can’t use if professionaly, but it seems a very good and affordable way to fight piracy in an intelligent manner.