> You could sue me for copyright infringement anyway, but you’d need to prove that my program copies yours. Some of the criteria used to prove this include the structure and organisation of the original source code, so even if I were to have used a different programming language, if I use the same code structure (even coincidentally) then it can appear as if I copied your program.<p>AFAIK, at least in the US, coincidence in and of itself is just fine, to prove infringement the copyright holder has to show that the defendant had access to the work, i.e. they actually copied it. This would seem to rule out most scenarios with a SASS/closed source plaintiff.