From retroj: I'm thinking something more on the scale of SLIME. The emacs mode
for repl interaction would need to transparently wrap the outgoing expressions
and unwrap the returned values, so on the UI side, the repl could look just like
a typical one, but beneath the UI would be an API for powerful programmatic repl
use. I don't see the reason to package something exactly like MozRepl in
conkeror, because MozRepl already works, as far as it goes.