Unfortunately the link crashes my browser (Chrome/Chromium, but a little out of date).

I'd be very interested to read about this, not least as I'm extending the untyped LC with a notion of a 'tag' term, and a branch on tag operation, thus resulting in dynamic dispatch without (formal) types.

Any pointers to a suitable graph reduction engine gratefully received, I've built my own naive implementation (in Javascript!) but of course it is rather slow.