A.3 Linux

If you have a Linux system, you have all the source code for the entire system available (this is also true for some Unix systems). (If it's not installed, you can get it from the distribution CDs, from the web site http://www.linux.org, or from the web site of the company that produced your version of Linux.) This is a great resource. You can take a look at how any program is actually written, even the operating system. Now you're really getting into programming!