I've always thought the Wiccan Rede would make a good software license:

"An it harm none, do what ye will"

partly because of the inevitable arguments about whether it's a free license or not

@vi It's not. A software under this license can't be used to make weapons for example.

@Sylvhem yeah, probably the same problem as the JSON "Don't be evil" license

@vi How, didn't know about this license! Sounds like a really bad idea…