There is also C23 and at some point C2Y.

C23 got typeof, constexpr constants, enums with underlying type, embed, auto, _BitInt, checked integers, new struct compatibility rules, bit constants, nullptr, initialization with {}, and various other improvements and cleanups. Modern C code - while still being simple - can look quite different than what people might be used to.

C2Y already already got named loops, countof, if with declarations, case range expressions, _Generic with type arguments, and quite a lot of UB removed from the core language. (our aim is also to have a memory safe subset)