[gregburd]

Lysp (http://piumarta.com/software/lysp/) is fairly close to what I'm guessing you're "pining" for and if not, hey it's open source so have at it!

[yoklov]

Lysp uses a lot of non-standard (and rarely implemented) extensions, and so would be very hard to use in most places.

The author's own Maru (http://piumarta.com/software/maru/) might be better suited for this, but I'm not sure..