Summary

The open source viewpoint is quite different from the viewpoint of proprietary software vendors. The source of the software must be open, available to everyone, not secret. Anyone is free to use the program for any purpose, to modify the program, or to redistribute the program. No permission required.

Most open source software development is organized as a project with volunteer developers, often located throughout the world, coordinating their work via the Internet. Open source software is posted on the Web as it is being developed, available for any interested person to use or to work on. Commercial companies in the open source world charge for enhancements to the software or for services related to the software, not for the software itself, as proprietary software companies do.

Like any other software, open source software comes with a license. The most common open source license is the General Public License (GPL). The GPL is quite unrestricted. It states that you can use the software for any purpose. You can change it if you want. You can redistribute it if you want. However, you cannot redistribute it as proprietary software. It must remain open source. Anyone receiving the software from you has the right to the source and has the right to change it or redistribute it.

Linux is an open source operating system. The heart of Linux is the kernel, but many additional programs are required to make your computer into a useful tool. Many of the additional programs are developed by the GNU (GNU's Not UNIX) project. The Linux kernel plus GNU programs plus additional programs and applications comprise the Linux system that sits on most computers today.

Although any user can download the Linux kernel and download all the components of a complete Linux system, it's not simple. Very few users install Linux in this manner. Rather, most Linux systems are installed from a distributiona collection of programs put together by a group or a company, often with a simplified installation procedure.

The characteristics of Linux distributions are discussed in Chapter 2. The range of distributions available and the focus of each are explained.