Hi Cafe. I came across an interesting page about interactive abstraction called "Up and Down the Latter of Abstraction" [1] while browsing hacker-news. Under the appendix "Tools & Implementation" Bret Victor ponders: "Perhaps language theorists will stop messing around with arrows and dependent types, and start inventing languages suitable for interactive development and discovery." I don't subscribe to the idea that static guarantees and functional characteristics are mutually exclusive to interactive development and discovery and I think they may actually complement each other extremely well, but this page certainly does sell the interactive aspect very effectively. The closest I've seen to this proces from Haskell seems to have come from "luite" and co (correct me if I'm wrong) and their work on the Diagrams package and its surrounding infrastructure [2], however, their interactive demonstrations no longer seem to be online. Still, the dominant interface seems to be web-based, and I feel that a native environment for this kind of explorative interactive programming would be more effective. Other languages that seem to be especially effective at this kind of development are Processing [3] and Mathematica [4]. Has anyone had experience with interactive development in Haskell? [1] - http://worrydream.com/LadderOfAbstraction/ -- "Appendix: Tools & Implementation" [2] - http://pnyf.inf.elte.hu/fp/Diagrams_en.xml [3] - http://processing.org/ [4] - http://www.wolfram.com/mathematica/