ChibiScheme (https://code.google.com/p/chibi-scheme/ https://code.google.com/p/chibi-scheme/) tries to be that. I've considered using it but have avoided it due

ChibiScheme (https://code.google.com/p/chibi-scheme/ https://code.google.com/p/chibi-scheme/) tries to be that. I've considered using it but have avoided it due to its relative newness and a few portability issues.