I like to think of it this way: if I'm writing an open-source library that I want others to include in their projects, the best way to get adoption (or to just

I like to think of it this way: if I'm writing an open-source library that I want others to include in their projects, the best way to get adoption (or to just make fellow dev's lives easier) is MIT/BSD/similar-style licensing. I personally don't mind if people cut or carve up my code, use it in closed-source, etc as long as they keep my name on it. When it comes to building an actual app that's open-source (and not meant to be included in other projects), GPL is a really great way to go. In my mind, it protects the end-users of the app such that it can never be infected by closed-source software, via me or by anyone else, as long as it stays GPL. For things like protecting a project against the hooked tentacles of the US government's spy machine, it's a great tool. Sure I can put in backdoors, but everyone in the world will see it.