Turn based servers such as Nodejs are now joining turn based browsers in providing race-free and deadlock-free interactivity. The event-driven model has long been popular in UI systems, but the nature of work in servers presents some new challenges. Functional programming provides solutions, including monads, arrows, promises, and various flavors of FRP. This is another such solution that uses asynchronicity, targeted specifically to the challenges of high performance JavaScript web applications.
Video producer: http://javazone.no/