HAC is a recursive acronym meaning HAC Ada Compiler. HAC isn’t a native code compiler but a Virtual Machine compiler which comes with a very compact and monolithic run-time executor.
HAC can be used for small Ada sand-boxed prototypes, education and scripting.
As an education tool, HAC is an excellent Ada subset for programming introduction.
As a script language, thanks for its shebang handling and its useful environment functions, HAC is the most Ada compact and powerful script engine you ever dream for. The HAC compilation is straightforward. The executor is ridiculously small and fully standalone. Move the hac program to your path and voila!
Last but not the least, HAC sources are fully compatible with Ada compilers, through the compatibility package HAT !
See document HAC Ada Compiler User Manual and HAC sources.