I just installed the 3.0 iphone open toolchain in cygwin (xp). I wrote my first helloword application: a simple Hello.m file where I: - import Foundation/NSObject,h and stdio.h - define a Hello class interface - implement the Hello class - wrote a main function that uses the Hello class. I tried to compile in this way: gcc -Wall Hello.m -lobjc -o hello The compiler return me the following message: Foundation: no such file or directory If I use objc/Object.h instead Foundation/NSObject it works. Please help me to overcame the problem? Path? Bad toolchain? wrong gcc command?