Molecule is a domain specific language library embedded in Scala for easing the creation of scalable and modular concurrent applications on the JVM. Concurrent applications are modeled as parallel process networks that exchange information over mobile and type-safe messaging interfaces. In this paper, we present a concurrent programming environment that combines functional and imperative programming. Using a monad, we structure the sequential or parallel coordination of user-level threads, without JVM modifications or compiler support. Our mobile channel interfaces expose reusable and parallelizable higher-order functions, as if they were streams in a lazily evaluated functional programming language. The support for graceful termination of entire process networks is simplified by integrating channel poisoning with monadic exceptions and resource control. Our runtime and system-level interfaces leverage message batching and a novel flow parallel scheduler to limit expensive context switches in multicore environments. We illustrate the expressiveness and performance benefits on a 24-core AMD Opteron machine with three classical examples: a thread ring, a genuine prime sieve and a chameneos-redux.

As users become more and more mobile and broadband access is being deployed at an ever-increasing pace, new ways of deploying services can be examined. Next to ways for accessing global services (portals), approaches are described to offer local services, based on the knowledge of the user's location in the nodes of the access network. Increasing the intelligence of the access nodes, localized, advanced and personalized services can be offered. Several methods are discussed to implement these local services, in order of increasing functionality.