Sodium - Reactive Programming in Java, Haskell and C++
(other languages to be added)

This is based on Flapjax, Yampa, scala.React and a number of other Reactive
programming efforts, as well as a lot of personal experience. Enjoy.

Status:
  Haskell - complete
  Java - complete (but see below)
  C++ - complete (but see below)
  Embedded-C - just an experiment
  Rust - got nowhere with it yet
 
A note on memory management:
  Memory management in Sodium is a complex business.

  The Haskell version's memory management has been perfected, which means that
  you can write arbitrarily complex code memory usage will stay constant. This
  proves that it can be done.

  The Java and C++ versions however are functionally correct, but they haven't
  been well tested for memory management yet. If you rip into using them, you
  may end up helping us with testing.

Drop by our blog at 
  http://reactiveprogramming.org/