I had my stint. I started a Python Web application framework called Aquarium seven years ago. It's now being used by IronPort all over the world. It's even been used in a couple apps at Yahoo.
In the Python Web world, we have about 1.5 times as many frameworks as we have programmers. I've heard people joke that you can't be a serious Python programmer until you've written your own templating engine in Python ;)
Ruby became mainstream, not thanks to its cool metaprogramming, but rather because DHH decided to write an app in it. Oh, and he also wrote some obscure Web framework that no one knows about ;)
One of the most "vocal" blogs supporting Erlang is Yariv's Blog. Erlang is wicked cool, so what does he do with it? He wrote a Web framework called ErlyWeb.
My buddy Alex Jacobson is a fascinating character. He's been coding in Haskell for almost as long as I've been coding in total. What's his project? HApps. It's labeled an "application server", but every time I see him playing with it, he's writing Web apps.
Surely, deep in the bowels of academia, there must be someone not interested in Web development. Someone, perhaps who only cares about computer science theory, right? For instance, Philip Wadler. He's made numerous contributions to Haskell and functional programming in general. He's presently a professor of Theoretical Computer Science in the School of Informatics at the University of Edinburgh. Surely he must be blissfully ignorant of this whole Web framework craze!
Nope, he's currently working on a new functional language designed for writing web applications called Links.