The first thing you need is to set up your build environment. For most of these examples, you can use any OS that supports GCC. If you're running on Mac OS X, install the development tools and you're done. For Ubuntu or Fedora, install the appropriate compiler packages and any dependencies. On Ubuntu, the build-essential package works well. For Fedora, install the Developer Tools grouplist and the gcc-objc package.
You'll also need the Foundation framework libraries and headers. Ubuntu keeps these in the libgnustep-base and libgnustep-base-dev packages. Fedora calls it gnustep-base-devel. Fedora also requires the gcc-objc package on top of the Developers Tools grouplist.
If you already know 'C', then you have a good basis for Objective-C. As the name implies, Objective-C is an extension of C, much like C++ is. Here is our first example source file example1.m:
