Some time ago I came across a really interesting paper, "Use of Prolog for developing a new programming language", by Joe Armstrong et al. Definitely worth a read.
It tells the story of a group of crazy Swedes who decided to use Prolog to build a prototype of this language that they were working on. They used this prototype to do lots of experiments, and because it was nice and tiny, they were able to rapidly evolve the language and its implementation. Rinse and repeat. (It was only about three years later that they finally had to do a "real" implementation.)
It's a great story about how great life can be when you ignore conventional wisdom and avoid premature optimization at all costs... BTW, the language was, of course, Erlang. :)