The C standard library is specified as part of the language specification document. The language defines two kinds of implementations: "hosted", which must sup

The C standard library is specified as part of the language specification document. The language defines two kinds of implementations: "hosted", which must support the entire standard library; and "freestanding", which do not. Those embedded systems that do not support the full standard library are 100% compliant freestanding implementations, but are not compliant hosted implementations.