defmacro on Lisp, Haskell, and RoR?
defmacro: The Nature of Lisp
I don't know Lisp yet, but it's (still) on my to-do list (stack). After reading this essay I feel an even stronger need to grok Lisp. This essay is a gentle introduction. Oh, and if you're into XML, or you're in the camp that prefers JSON or YAML, I think you'll get something from it as well.
There's another (much shorter) article from the same site:
This one (briefly) mentions Haskell, a language I started to learn earlier this year, and so far really enjoy.
I suppose I might as well continue: there's another article on defmacro about Web Applications in Haskell...
defmacro: Haskell and Web Applications
This one mentions Ruby on Rails, and shows how to do similar things in Haskell.