I am looking to start an experimental project using a functional languageand am trying to decide beween Erlang and Haskell, and both have some points that I really like. I like Haskell's strong type system and purity. I have a feeling it will make it easier to write really reliable code. And I think that the power of Haskell will make some of what I want to do much easier.On the minus side I get the feeling that some of the Frameworks for doing web stuff on Haskell such as Yesod are not as advanced as their Erlang counter parts.I rather like the Erlang approach to threads and to fault tolerance. I have a feeling that the scalability of Erlang could be a major plus. Which leads to to my question, what has people's experience been in implementing web application backends in both Haskell and Erlang. Are there packages for Haskell to provide some of the lightweight threads and actors that one has in Erlang?
Haskell vs Erlang for web services
functional programming;haskell;erlang
The only question I have is what is your web service doing?  If the web service is truly a functional problem, then Haskell will be a better fit.Erlang isn't necessarily a functional language.  It's a procedural language with a very strong execution model for massively parallel systems.  It was designed for the telecom industry, and it would definitely make an excellent fit for responding to web service requests.See this page* for an overview of the differences between procedural and functional programming.  (Apologies in advance for the ugly black on cyan page).If your web service is doing a fair amount of pattern matching and applying rules, then Haskel is your choice.  If you just want a scalable infrastructure that isn't too different from the languages you probably already know, choose Erlang.(* link via Wayback machine. Original file has been removed)