Not too long ago I had this idea that browsers should just be specialized Lisp interpreters. EMACS has a web browser called W3. But I've seen it, and it's not so good. I think a specialized browser application would be far more successful.
Maybe we just need something different. Maybe instead of sending static pages with mini-embedded languages, we should just send the whole program... as a Lisp script. If the browser itself were just a Lisp interpreter, than interpreting the incoming script should be trivial. Also notice how much of a load this would take off servers. They would no longer need to execute much business logic. Instead, the server would be responsible for extracting information from the database, performing the minimum number of calculations needed on the server side, and then send the Lisp (data, code and all) right over to the client.
Sometimes I wonder if Lisp interpreters shouldn't be like DSPs. We could put a little embedded Lisp interpreter in everything. You wouldn't even need know that they were there. But the engineers will know, and they'll make heavy use of them.