This is neat. The language is defined with braces and semicolons. But:
Haskell permits the omission of the braces and semicolons used in several grammar productions, by using layout to convey the same information. This allows both layout-sensitive and layout-insensitive styles of coding, which can be freely mixed within one program. Because layout is not required, Haskell programs can be straightforwardly produced by other programs.
I remember the first time I tried to embed Python into a web page and I realized I had to figure out how to make the whitespace work out so my if statements would work. Haskell's system allows really simple and good-looking code for the common case (I don't think I've ever seen a curly brace in any Haskell code) but still can be defined as whitespace-insensitive.
By the way, Haskell code is totally hot. Even though I still can't figure out how to use it.
(Cut 'cause I'm afraid I'm posting too much.)