Linux Is Open Source Software

Linux is an operating system. It makes your computer hardware into a usable machine. It interacts with the hardware to perform the tasks you need done, such as store information in files, display information on the screen, send data to the printer, add two numbers together. Anything you do on your computer is mediated by the operating system.

Linux is not one big, monolithic program. It is a collection of many programs that together make your computer into a useful tool. The heart of Linux is the kernel where the low-level operations take place. Without the kernel, there's nothing. However, the kernel by itself is not enough. Many other programs combine to make up the Linux operating system that sits on your computer. More details regarding the programs required are provided in Chapter 2.

Linux is based on the UNIX operating system, which was developed in the 1970s to run on mainframe and minicomputers. In 1991, a student at the University of Helsinki in Finland, named Linus Torvalds, wanted an operating system like UNIX to run on his PC. Because nothing meeting his requirements existed, he set out to write one. The current Linux kernel is the resultproduced by the work of developers all over the world, coordinated by Torvalds. When he posted his project to the Web early in its development, he found a great deal of interest. It seemed many people wanted an operating system like this and jumped in to help. Linux was released almost every week and immediate feedback from hundred of users was incorporated into its development, facilitated by the rapid growth of the World Wide Web.

From the beginning, Linux was open source. It was distributed freely to anyone who wanted it. The official Web site for Linux, where the latest news is available and the current source can be downloaded, is www.linuxhq.org (Linux Headquarters).

Other programs that make Linux useful on your computer can be downloaded from various Web sites. A central source for Linux utilities, compilers, applications, and other software is GNU (discussed later in this chapter). Many other individual project and company Web sites exist for software that is part of a complete, installed Linux system.

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. Linux distributions are discussed in Chapter 2.