Haskell. Hoogle. Hoogle is a Haskell API search engine, which allows you to search many standard Haskell libraries by either function name, or by approximate type signature.
Example searches: map (a -> b) -> [a] -> [b] Ord a => [a] -> [a] Data.Map.insert Enter your own search at the top of the page. The Hoogle manual contains more details, including further details on search queries, how to install Hoogle as a command line application and how to integrate Hoogle with Firefox/Emacs/Vim etc. I am very interested in any feedback you may have. Platform.