http://news.ycombinator.com/item?id=1703902 http://news.ycombinator.com/item?id=1703902 You can build onto GPL for free without reciprocating. That's called fr

http://news.ycombinator.com/item?id=1703902 http://news.ycombinator.com/item?id=1703902 You can build onto GPL for free without reciprocating. That's called freedom 1: the right to private modifications.