[LesZedCB]

What is the defacto IDE/editor for Haskell? I've messed around with Leksah, which looks like it's pretty nice, but I have absolutely no idea how it works.

[fusiongyro]

There really isn't a de-facto IDE/editor. The Emacs support continues to improve; Vim support is quite strong. There's EclipseFP for Eclipse. I have used Leksah and like it, but usually use TextMate.

[pjmlp]

If you don't have any religious issues with Java or Eclipse, then EclipseFP is the best one currently, http://eclipsefp.github.com/.

[MtnViewMark]

I use Leksah for larger projects. I use just my favorite text editor (Sublime Text 2) and cabal/ghc/ghci in a shell window for smaller.