| Using Haskell for this networking app forced me to focus on all the | issues _but_ the business logic. Type constraints, binary IO and | serialization, minimizing memory use and fighting laziness, timers, | tweaking concurrency and setting up message channels, you name it. That's a disappointing result. Mostly I think Haskell lets you precisely focus on the logic of your program, because lots else is taken care of behind the scenes. You found precisely the reverse. It'd be interesting to understand which of these issues are - language issues - library issues - compiler/run-time issues My (ill-informed) hypothesis is that better libraries would have solved much of your problems. A good example is a fast, generic serialisation library. If you felt able (sometime) to distil your experience under headings like the above, only more concretely and precisely, I think it might help to motivate Haskellers to start solving them. Simon