I thought the link would be of companies that use Haskell as their primary language of development, but it is more of companies which use/had used Haskell in one of their projects. The former would be interesting to know, if indeed such companies exist.
Haskell has much more of a group inside of a company will use it as their primary environment then adopting it wholesale. Haskell is used extensively in trading with almost every major bank and hedge fund using it, although no one talks about it. It is also extensively used in energy companies.
There are a few companies out there that use it as their primary language such as Tsuru Capital and my company, Alpha Heavy Industries. By definition companies using it as their primary language will be smaller companies. Standard Chartered has a very large Haskell group.
That Haskell is used extensively in trading is quite interesting to know. This distinction did not come out that well on the wiki link. This is probably the reorganization that the page needs. Split in to sections highlighting companies which use Haskell as primary language, then split along industry lines.
Highlighting companies which use Haskell as primary language will be beneficial to both the language and the companies. Brings along a trust factor that real money can be made while using on Haskell.
Depending on how some endeavors pan out, my wee company, WellPosed, is likely to be in that rarified category in the near future :-)
(strictly speaking it may be 2-3 distinct enterprises under the same umbrella, but same thing). Also some interesting stuff on the algorithmic & open source pipeline that'll be made available as those services come out.
(a vague summary of the pending products/services can be seen in this month's who's hiring thread.)
That would probably limit a lot the number and diversity of the potential candidates. As a complete outsider I find more interesting that Haskell is used for even few projects inside, say, Credit Suisse than a one-man shop nobody has heard of that uses Haskell exclusively; YMMV.