Thanks for your support. Like I mentioned, I will circle back to Haskell as the business develops. If I was the only programmer in my startup, I would likely go with Haskell for important components of our software. But I have concerns about hiring a large team that would thrive in Haskell. One never knows - I'm keeping an open mind :)

Hmm, I'm not convinced that hiring a team of good developers for Scala is all that much harder than hiring good Haskell programmers. Haskell has a disproportionate number of very capable people interested in it, and from what I've heard acts as both a way to attract top developers and as something of a filter (at least in encouraging applicants to be more self-selected).

I think these effects cancel out Haskell's relative lack of popularity unless you expect to be hiring at the enterprise Java level--something like literally thousands of developers.

Anyhow, keeping an open mind is the most important thing, and you clearly have no problems there. I just wish others would follow suit in that regard.

"The core of ZLemma.com is a mathematical framework involving highly structured data representations and numerical algorithms."

You might also consider a Haskell core, surrounded by a Python website. (Or any other website language/framework you like.) It strikes me as likely you have some sort of relatively small interface you can define between those two things, and then you can use the strengths of everything.

I am with you on this. More on this in Part 2 of the post.

Haskell's syntax is weird compared to more popular languages. This is the main reason it's hard.

That said, It's a better choice than Scala for math. However, if the math is numerical algorithms, Python is better than either Haskell or Scala.

I'm not sure why they need to settle on one language. Seems like painting the bike shed. For better or worse, every sufficiently large web system has a number of languages being used behind the scenes.

Syntax is by far the most superficial difference. If you're going to actually use functional programming, the trick will be learning the paradigm and not worrying about syntax. In fact, from that perspective, I think Haskell syntax actually wins out: it's extremely simple and very well-suited to functional programming. I found things like curried functions and recursion much easier to grasp and use in Haskell than in Scheme when I was learning both simultaneously.

I certainly do not think that syntax is anywhere near why some people find Haskell hard to pick up. Thanks to pattern matching, the syntax is very visual and thanks to having relatively few forms and keywords, it's much simpler than most imperative languages'.

Also, I'm not suggesting necessarily using Haskell exclusively, by any means; I just want more people to consider it at all!

Well, I'm still not so sure. I've been doing functional programming for 20 years and I thought Haskell syntax was weird.

I find Haskell's syntax very attractive. It is the same style in which one would express domains and operations on a whiteboard.