Interesting. I am a co-author on the Methanal <https://launchpad.net/methanal> library which is more-or-less this same combinator approach but tightly coupled to Nevow Athena.

I recently (as near as a week ago) started working on a modern JavaScript implementation of the same idea but without the tight coupling to a particular framework.

Very strange coincidence. :)

Here's a pure Python implementation: https://github.com/jerith/depixel

Thanks!

See? Even he doesn't know what to call it!

A work in progress implementation, anyway.