Gnu Cee

CeeLanguage with the extensions supported by gcc (GnuCompilerCollection). Many of these extensions are in C99; of those that are not, the most useful and/or interesting are:

GoTo labels as values (used by some VirtualMachine implementations),
typeof(...) to refer to the type of an expression,
nested functions (see NestedScopes) with LexicalScoping,
compound statements as expressions.

http://gcc.gnu.org/onlinedocs/gcc-4.0.2/gcc/C-Extensions.html

This compiler will also compile ObjectiveCee and (on MacOsx) ObjectiveCeePlusPlus.