What platforms are we talking about? Anything actually used by consumers or business or is it all just stuff that has esoteric support by hobbyists and those cr

What platforms are we talking about? Anything actually used by consumers or business or is it all just stuff that has esoteric support by hobbyists and those creating custom and reviving super old stuff. I would imagine that if someone's platform doesn't support C11 at this point it pretty much hasn't been updated in 7 years and pretty much can't custom build GCC. I mean I know how to build GCC on a Sega Dreamcast so it has to be more esoteric than that. Also, not supporting C11 probably also means not supporting lots of other things that modern applications might want like Vulkan, IPv6 or multiple threads.