> does SWIG (or hand-writing C bindings) have any advantages over
Ruby/DL?

I don't know, but having struggled with SWIG lately, I'm going to see
if Ruby/DL does a better job; it certainly looks cleaner than a direct
native binding solution.

Takaaki Tateishi, are you still alive?  You started Ruby/DL2, but
haven't worked on it in a while... what is the status of the project?
--- SER