Haskell has a mutable variable implementation here: http://hackage.haskell.org/packages/archive/base/4.0.0.0/doc/html/Control-Concurrent-MVar.html http://hackag

Haskell has a mutable variable implementation here: http://hackage.haskell.org/packages/archive/base/4.0.0.0/doc/html/Control-Concurrent-MVar.html http://hackage.haskell.org/packages/archive/base/4.0.0.0/doc... It also has a software transactional memory implementation here: http://hackage.haskell.org/package/stm http://hackage.haskell.org/package/stm STM in particular is a neat way to do concurrency. http://www.haskell.org/haskellwiki/Software_transactional_memory http://www.haskell.org/haskellwiki/Software_transactional_me...