New concise guide I am creating: http://www.coolpage.com/commentary/economic/shelby/Functional_Programming_Es... I was able to condense Category theory and implementation of Monads to one screen: http://www.coolpage.com/commentary/economic/shelby/Functional_Programming_Es... Overall, I think I have a unique method for comparing and condensing the explanation of the transistion from imperative to pure functional. What you think? It is a work-in-progress, so corrections, feedback, and flames are welcome. I will do the OOP section next and incorporate the explanations from these posts: http://www.haskell.org/pipermail/haskell-cafe/2009-November/068440.html (data vs. Module) http://www.haskell.org/pipermail/haskell-cafe/2009-November/068432.html (interface vs. virtual) P.S. The link will not change if you want to link to it now. If you mirror it, please update your mirrors periodically. There is no copyright claimed, I don't believe in copyrights any more. I intend to publish everything as PUBLIC DOMAIN (i.e. no license at all, because licenses impact composability). If I want to charge, I will put functionality behind an unpublished interface (i.e. Module). P.P.S. I only started learning functional programming about a week ago.