Section 1.3. Free Software and Open Source

1.3. Free Software and Open Source

Linux is one of the most successful examples of open-source software. Open-source software is software whose source code is freely available such that anyone can modify, read, and redistribute it. This stands in contrast to the closed-source software distributed only in binary form.

Open source allows a user to develop the software at will to suit his own needs. Depending on the license, certain restrictions apply to the code. The benefit of this is that users are never limited by what has been developed by others because they can freely alter the code to suit their needs. Linux provides an operating system that allows anyone to develop and contribute to it. This caused a fairly rapid evolution of Linux as the rate of involvement, whether in development, testing, or documentation, is staggering.

Various open-source licenses exist: In particular, Linux is licensed under the GNU General Public License (GPL) version 2. A copy of the license can be found at the root of the source code in a file called COPYING. If you plan on hacking the Linux kernel, it is a good idea to become familiar with the terms of this license so that you know what the legal fate of your contribution will be.

There are two main camps around the conveyance of free and open-source software. The Free Software Foundation and the open-source groups differ in ideology. The Free Software Foundation, which is the older of the two groups, holds the ideology that the word free should be applied to software in much the same way that the word free is applied to speech. The open-source group views free and open-source software as a different methodology on par with proprietary software. For more information, go to http://www.fsf.org and http://www.opensource.org.