hmmmm……

What are the limitations to gpl compared to public domain?

The only ones I think of are good given the status of copyright law and attitude so…

I won’t be joining the FSF.

I strongly disagree with the ethics of their GPL; they make Bush-like redefinitions of the terms “free” (=”copyrighted”) and “compatible license” (=”overridable by GPL”); they strongly discourage people from releasing into the public domain; they strongly discourage people from using their own LGPL because it’s too open; they lobbied to move US Gov’t contracted code into the GPL rather than the public domain where it belongs; they encourage people to sign patents over to them; they encourage people to write copyrighted code; and so on.

The GPL is viral: if applied to a fork of a public domain project, it will eventually have to be applied to the main project, as changes in the fork cannot legally be reapplied to the trunk, but trunk changes can be applied to the GPL fork.

The GPL has hugely damaged the public domain programming community that predated it. Once there was a healthy base of public domain code: now everything’s released under copyright.

Far better, then, to give money to other causes: ORG, EFF, CC, et al. These are organisations that fight against DRM and for open source, without treating the public domain as an evil to be exterminated. Sure, Creative Commons does use viral copyright licences, but it also embraces the Public Domain, and offers it as an option at the same level as any other.