conal:
Reactive [1] is a library for functional reactive programming (FRP), similar to the original Fran [2] but with a more modern interface (using standard type classes) and a hybrid push/pull implementation. It is designed to be used in a variety of contexts, such as interactive 2D and 3D graphics, graphical user interfaces, web services, and automatic recompilation/re-execution. It has a simple and precise semantics based on continuous time and is built on a notion of functional future values. The semantics and implementation are described in the paper "Simply efficient functional reactivity" [3].
Reactive now has a mailing list [4] and a feature/bug tracker [5].
And now available for Arch Linux, http://aur.archlinux.org/packages.php?ID=17854