Hi! I have just published my library which provides a general data-flow framework: http://hackage.haskell.org/package/Etage Sadly it requires current GHC HEAD branch because of this: http://hackage.haskell.org/trac/ghc/ticket/1769 Short description: A general data-flow framework featuring nondeterminism, laziness and neurological pseudo-terminology. It can be used for example for data-flow computations or event propagation networks. It tries hard to aide type checking and to allow proper initialization and cleanup so that interfaces to input and output devices (data or events producers or consumers) can be made (so that created models/systems/networks can be used directly in real world applications, for example robots). I am more than open to any suggestions and comments. Mitar