I'm trying to do app dev, either on linux or on the ipod itself. I've created a Hello World example which I can compile directly on the iPod itself. (Using the "2.0 Compatibility Toolchain" downloaded from Cydia.) I was then learning more about Objective-C and noticed the example I was using extended UIApplication as opposed to just implementing the UIApplicationDelegate "protocol". So I change the example to use this but it cannot compile because: WindowApp.h:12: error: cannot find protocol declaration for 'UIApplicationDelegate' Okay this makes sense, I don't see this in the headers in: /var/include/UIKit/ Some googling led me to this thread: http://www.hackint0sh.org/forum/f9/53541-2.htm where someone points out about a different app: I've read saurik's instructions for building on linux here: http://www.saurik.com/id/4 This seems insanely complicated. Do I really need a .dmg from the ipod filesystem itself? Also I'm having trouble finding the "iPhone2.0 SDK" (I'm guessing this has the headers and libs I need for things like UIApplicationDelegate?) It seems I need to register as a developer on apple's site to download this SDK. Do they really need my name, address and phone number? Does the GPL'ed code or other licensed code they themselves are using even allow this restriction? ------------------double post merged------------------Quite a few thread views but no responses. I'm new here so maybe I'm asking really stupid questions....? I've gone ahead and bit the bullet and registered as an apple developer. I downloaded their iphone SDK. This is a .dmg image. And it can't be mounted with "-t hfs" since it's a "VAX COFF executable not stripped" which googling shows is some Apple image format that includes partition info. Something called "hfsexplorer" (which is a java app) can be used to extract this. I only found this as an .EXE installer with .EXE launcher/wrapper. So you can install it with wine, grab the underlying jars in it's lib dirs and run it manually using "java" from the shell prompt. Now I see this image contains a dir called "Packages" which contains files with .pkg extensions. Are these SVR4 packages? Code: $ file iphoneSDK/Packages/DevSDK.pkg iphoneSDK/Packages/DevSDK.pkg: data What do I do with "data" files? ------------------double post merged------------------Sorry to keep automerge replying to my own thread. Seems this thread: http://www.ifans.com/forums/showthread.php?t=97672 covers the .pkg extraction.