Protecting & Promoting Open Source Software in A Contract

I’ve got an interesting question that I have no answers to yet: How can I protect Free and Open Source Software (FOSS) development while working as a contract programmer? Specifically, how can I promote the development of small libraries like Ruby Gems and make sure that it is both understood, accepted, and most of all legal? Using Free Stuff, Is It “Take” Only? I’m not talking about stealing...