The AUX compiler supports several languages: Ada, C, C++, Fortran and Objective-C. Since Ada support must be built by an Ada-capable compiler, only platforms for which a bootstrap compiler is available can build it. The AUX compiler is based on release versions of the Free Software Foundation's GNU Compiler Collection. It carries with it the GMGPL license, the modified version of the GPL that exempts generic instantiation from resulting in a GPL-licensed executable. It also carries the GCC Runtime Library Exception, so the resulting binaries have no licensing requirements. Binaries produced by the AUX compiler should be legally handled the same as binaries produced by any FSF compiler. This compiler implements the full Ada-83, Ada-95, Ada-2005 and Ada-2012 standards.