But where are all the successful large scale projects built with Haskell (or Clojure or whatever)?
Standard Chartered has a huge amount of infrastructure in Haskell. Clojure's too young to have the types of stories you're looking for, but it's had plenty of moderate-sized successes (as has Haskell).
The biggest FP project I was aware of was Twitter using Scala and they ended up completely backing away from it. Yikes.
Scala is different from Haskell. Scala has a lot of features that don't play well together, it has stability issues, and it has inherited some of the Java culture which means that there's a lot of terrible Scala code out there.
I've been working with Spark over the past month and I'm shocked by how bad the JVM/Hadoop legacy is. Spark itself is a neat idea. Getting it to work on an actual production cluster is a huge PITA. I'm tempted to just use Cloud Haskell.
I know people who've moved away from Scala (either to Java or Clojure or Haskell). No one who's moved to Haskell has ever regretted it. I know of about 15 companies that use it (not all on million-line projects) and they're all happy with it. I'm only aware of one case, in the past 7 years, where a company moved away from using Haskell: they moved to F# because they picked Microsoft up as a client and MSFT wanted to be able to say that $COMPANY_X was using their products.
The only other popular site that springs to mind is Hacker News, and frankly, it sucks. It's practically the Hello World of discussion forums.
It's written in Arc, which lost to Clojure. Also, HN is as good as it needs to be. It's successful on its own terms. It doesn't need to be a wonder of software engineering.
It will be once it gets a decent mobile view akin to viewing reddit on /.compact.
Anyway, good point--I've heard people complain that Haskell is hard to learn/understand, but I've never heard of anyone actually using it in production and regretting that decision.
Standard Chartered has a huge amount of infrastructure in Haskell. Clojure's too young to have the types of stories you're looking for, but it's had plenty of moderate-sized successes (as has Haskell).
The biggest FP project I was aware of was Twitter using Scala and they ended up completely backing away from it. Yikes.
Scala is different from Haskell. Scala has a lot of features that don't play well together, it has stability issues, and it has inherited some of the Java culture which means that there's a lot of terrible Scala code out there.
I've been working with Spark over the past month and I'm shocked by how bad the JVM/Hadoop legacy is. Spark itself is a neat idea. Getting it to work on an actual production cluster is a huge PITA. I'm tempted to just use Cloud Haskell.
I know people who've moved away from Scala (either to Java or Clojure or Haskell). No one who's moved to Haskell has ever regretted it. I know of about 15 companies that use it (not all on million-line projects) and they're all happy with it. I'm only aware of one case, in the past 7 years, where a company moved away from using Haskell: they moved to F# because they picked Microsoft up as a client and MSFT wanted to be able to say that $COMPANY_X was using their products.
The only other popular site that springs to mind is Hacker News, and frankly, it sucks. It's practically the Hello World of discussion forums.
It's written in Arc, which lost to Clojure. Also, HN is as good as it needs to be. It's successful on its own terms. It doesn't need to be a wonder of software engineering.