Am I out of line to expect some sophisticated Haskell programs to exist before taking this claim seriously?
is there as much haskell out there as c, perl, python? no. but if you want to be a pioneer you have to drive on a little dirt. but don't worry, we'll keep plugging away and in no time at all the haskell highway will be lined with HoJos and rest stops and miles of flat-top...we'll send you a postcard.
How about not.
Languages get adopted because they make new things possible/easier, not because they're good for re-inventing the wheel.
Of course, "make new things possible" is a tricky thing to make sense of. What new thing did Python make possible? Or Ruby? Or PHP? Or Perl?
I'm not sure about which features originated in dwm vs. xmonad (there seems to be cross-pollination of ideas between the two, so that's a good thing either way), and I haven't used house or camp.
Innovative does not mean valuable, or, more important, popular.
I proposed the theory that languages become popular because they make creating new things possible and/or easier.
If Darcs qualifies as such a new thing, the fact that it didn't help popularize haskell argues against my theory.
Maybe my theory is wrong. (I'd certainly patch it in certain ways.) Maybe Darcs doesn't qualify. Maybe Darcs didn't do the trick because no one knows about it.
So, let's flip the question. What has the Haskell community done that has been important in making other languages popular in the past? If they're not doing any of those things, why should Haskell nevertheless become popular? (Note that lots of "superior" languages never became popular, so if you're going that route, you get to explain why Haskell will be different.)
(XMonad is a much less significant example for Haskell's popularity, IMHO.)
It seems highly likely to me that Haskell's type system made inventing Darcs's theory of patches significantly easier. While a Darcs-like system could be written in C, designing the system as a whole was almost certainly aided greatly by Haskell's type checking and lightening of certain conceptual burdens through laziness.
Besides, I don't think I should need to spend all of my waking time coding; I already spend several hours a day doing that. Why can't I take a break to argue that Haskell's tools make the language more production focused than most people realize?