The same goes for uzbl, too, of course. Things like the Grail Browser [1] (a Python webbrowser, including the possibility to run client-side python-code - but sadly obsolete and not maintained anymore, as far as I can tell) are so much cooler than just tying webkit to GTK using $LANGUAGE.
I mean, it's not like HTML layout engines or JS-interpreters are somehow impossible to write from scratch.