All, At http://projects.haskell.org/ghc-iphone/ there's a new GHC-iPhone binary, version 1.6. Direct URL is http://dev.ipwnstudios.com/ghc-iphone/ghc-iphone-binary-1.6-sdk-4.2.tar.bz2 The source code, in the form of patches is at http://projects.haskell.org/ghc-iphone/patches/sdk4.2-on-snowleopard/ This is just the old GHC-6.10.4 to iPhone cross compiler, built on Snow Leopard and updated to work with Xcode 3.2.5 and iOS SDK 4.2. Set your project SDK to 4.2. (Select top level of project tree at left and select Get Info, then go to the 'Build' tab and scroll down. Do this once for Simulator and once for Device.) Compiling to old SDKs - necessary for app store deployment: When I set SDK to iOS 4.2 and 'deployment target' to iOS 3.0, the code worked fine on my old iPod Touch with iOS 3.0 installed. Steve