...At least for ASIS, the components used to build it must match the components in the compiler, so if building ASIS for use with (for example) FSF GCC 4.8.0 a version of GNAT Util is needed which contains components from FSF GCC 4.8.0.
This project provides such a library.
The code is released under GPL V3.0 without any Runtime Exception, because the compiler components are themselves pure GPL.
NOTE: This library was written to support building Ada tools for Darwin (Mac OS X), and contains Darwin-specific choices.