Does anybody bother about the stuff after C99?
MSVC just got C11 support a little over a year ago, so you won't see many big cross-platform projects using it yet, unfortunately. Some projects can optionally use C11 stdatomic.h and stdalign.h to replace old OS and compiler-specific extensions, but most of them still keep fallback code in case C11 isn't available.
Re: C meeting is over. C23 added:
#361You could also use GCC's mingw platform to target windows, which supports all the same modern C features GCC does for other targets.