title: Haskell vs JVM performance
body: <p>I want to write a backend system for a web site (it'll be a custom search-style service). It needs to be highly concurrent and fast. Given my wish for concurrency, I was planning on using a functional language such as Haskell or Scala.</p>
  
  <p>However, speed is also a priority. <a href="http://benchmarksgame.alioth.debian.org" rel="nofollow">http://benchmarksgame.alioth.debian.org</a> results appear to show that Java is almost as fast as C/C++, Scala is generally pretty good, but Haskell ranges from slower to a lot slower for most tasks.</p>
  
  <p>Does anyone have any performance benchmarks/experience of using Haskell vs Scala vs Java for performing highly concurrent tasks? </p>
  
  <p>Some sites I've seen suggest that Scala has memory leaks which could be terrible for long running services such as this one. </p>
  
  <p>What should I write my service in, or what should I take into account before choosing (performance and concurrency being the highest priorities)?</p>
  
  <p>Thanks</p>