I should add that substantively, the conclusion that programming languages can't be copyrighted is relatively well supported from past cases. Generally one can'

I should add that substantively, the conclusion that programming languages can't be copyrighted is relatively well supported from past cases. Generally one can't copyright rules to a game or contest, and one can't copyright facts or algorithms. This principle has been extended, at least in the US, to the whole idea that one cannot copyright systems and processes (see §102 of the copyright act). This is slightly more complicated in the EU because of the Information Directive and the Software Directive, which grants copyright to more portions of software than the common law used to, and also gives copyright to 'intellectual works' (whether this is the same as an 'original work' requirement in the common law world is still up for debate).