What if they use a custom process so that the binary with the standard process will be a "little" bit different? Actually both used the same source, but a different set of tooling, maybe even a special plugin for clang to get ubuntu.com somewhere into the binary file. is the binary still copyright fee or isn't it? actually what if it is gpl, does gpl also mean, that the compiler needs to be gpl? what if the compiler adds something, i.e. a ubuntu trademark? I mean i could even sell the binary. i just need to give the source since gpl only applies to the source level, the question about the packaged file is actually left out and I don't think I could resell it without recompilation if somebody copyrights 'his' binary.