Chapter 1: Introduction to Red Hat Linux

Overview

Linux is a fast, stable, and open source operating system for PC computers and workstations that features professional-level Internet services, extensive development tools, fully functional graphical user interfaces (GUIs), and a massive number of applications ranging from office suites to multimedia applications. Linux was developed in the early 1990s by Linus Torvalds, along with other programmers around the world. As an operating system, Linux performs many of the same functions as Unix, Macintosh, Windows, and Windows NT. However, Linux is distinguished by its power and flexibility, along with being freely available. Most PC operating systems, such as Windows, began their development within the confines of small, restricted personal computers, which have only recently become more versatile machines. Such operating systems are constantly being upgraded to keep up with the ever-changing capabilities of PC hardware. Linux, on the other hand, was developed in a different context. Linux is a PC version of the Unix operating system that has been used for decades on mainframes and minicomputers and is currently the system of choice for network servers and workstations. Linux brings the speed, efficiency, scalability, and flexibility of Unix to your PC, taking advantage of all the capabilities that personal computers can now provide.

Technically, Linux consists of the operating system program, referred to as the kernel, which is the part originally developed by Linus Torvalds. But it has always been distributed with a massive number of software applications, ranging from network servers and security programs to office applications and development tools. Linux has evolved as part of the open source software movement, in which independent programmers joined together to provide free quality software to any user. Linux has become the premier platform for open source software, much of it developed by the Free Software Foundation's GNU project. Many of these applications are bundled as part of standard Linux distributions. Currently, thousands of open source applications are available for Linux from sites like the Open Source Development Network's (OSDN) sourceforge.net, the software depositories rpmfind.net and freshmeat.net, KDE's apps.kde.com, and GNOME's www.gnome.org.

Along with Linux's operating system capabilities come powerful networking features, including support for Internet, intranets, and Windows and Apple networking. As a norm, Linux distributions include fast, efficient, and stable Internet servers, such as the Web, FTP, and DNS servers, along with proxy, news, and mail servers. In other words, Linux has everything you need to set up, support, and maintain a fully functional network.

With the both GNOME and K Desktop, Linux also provides GUI interfaces with that same level of flexibility and power. Unlike Windows and the Mac, Linux enables you to choose the interface you want and then customize it further, adding panels, applets, virtual desktops, and menus, all with full drag-and-drop capabilities and Internet-aware tools.

Linux does all this at the right price. Linux is free, including the network servers and GUI desktops. Unlike the official Unix operating system, Linux is distributed freely under a GNU General Public License as specified by the Free Software Foundation, making it available to anyone who wants to use it. GNU (the acronym stands for "GNU's Not Unix") is a project initiated and managed by the Free Software Foundation to provide free software to users, programmers, and developers. Linux is copyrighted, not public domain. However, a GNU public license has much the same effect as the software's being in the public domain. The GNU general public license is designed to ensure Linux remains free and, at the same time, standardized. Linux is technically the operating system kernel, the core operations, and only one official Linux kernel exists. People sometimes have the mistaken impression that Linux is somehow less than a professional operating system because it is free. Linux is, in fact, a PC, workstation, and server version of Unix. Many consider it far more stable and much more powerful than Windows. This power and stability have made Linux an operating system of choice as a network server.

To appreciate Linux completely, you need to understand the special context in which the Unix operating system was developed. Unix, unlike most other operating systems, was developed in a research and academic environment. In universities, research laboratories, data centers, and enterprises, Unix is the system most often used. Its development has paralleled the entire computer and communications revolution over the past several decades. Computer professionals often developed new computer technologies on Unix, such as those developed for the Internet. Although a sophisticated system, Unix was designed from the beginning to be flexible. The Unix system itself can be easily modified to create different versions. In fact, many different vendors maintain different official versions of Unix. IBM, Sun, and Hewlett-Packard all sell and maintain their own versions of Unix. The unique demands of research programs often require that Unix be tailored to their own special needs. This inherent flexibility in the Unix design in no way detracts from its quality. In fact, this flexibility attests to the ruggedness of Unix, allowing it to adapt to practically any environment. This is the context in which Linux was developed. Linux is, in this sense, one other version of Unix—a version for the PC. The development of Linux by computer professionals working in a research-like environment reflects the way Unix versions have usually been developed. Linux is publicly licensed and free—and reflects the deep roots Unix has in academic institutions, with their sense of public service and support. Linux is a top-rate operating system accessible to everyone, free of charge.

As a way of introducing Linux, this chapter discusses Linux as an operating system, the history of Linux and Unix, the overall design of Linux, and Linux distributions. This chapter also discusses online resources for documentation, software, and newsgroups, plus Web sites with the latest news and articles on Linux. Web and FTP site listings are placed in tables for easy reference. Here you can find sites for different distributions, Linux publications, software repositories, and Linux development, as well as for office suites and commercial databases.