About Linux

On this page:

• Introduction
• Distributions
• Common package management programs
• Availability
  • Obtaining Linux on CD-ROM
  • Obtaining Linux on the Internet
• Support at IU
• Online documentation

Introduction

Linux, originally created by Linus Torvalds, is an operating system that is freely distributed under the terms of the GNU Public License. It behaves like Unix, but does not come from the same source code base. Linux is available in both source code and binary form.

Linux offers standard Unix features, such as multiuser support, multitasking, networking, and POSIX compliance. It supports all the standard Unix utilities and can compile most major Unix packages with little effort. DOS emulation is also available, and an X Window System-based Microsoft Windows compatibility layer, called Wine, is in development.

The complete Linux operating system consists of the Linux core, or kernel, combined with the utilities and applications required for a fully functional operating system. There are several such combinations, called distributions, put out by various companies, and there is no such thing as an official version.

Distributions

The Linux operating system is available as many different distributions, each of which contains the Linux kernel, a variety of installation and application programs, and other customized features. Some distributions are very similar to each other with only minor differences, while other distributions have some significant differences. Also, some distributions are designed for specific types of computers.

Some major distributions include Red Hat, Ubuntu, Debian, SuSE, Mandriva, Gentoo, and Slackware.

Each distribution has its own individual strengths and weaknesses. Some of the more prominent distributions are compared in the document "English-language GNU/Linux distributions on CD-ROM". This document is posted regularly to the newsgroup comp.os.linux.answers.

Common package management programs

Many Linux distributions offer a package management system to simplify the processes associated with installing, removing, upgrading, and configuring various software packages for your computer. In a package management system, software is distributed in packages that include information dictating how the software should be installed. In addition to ensuring your software will be installed appropriately, the package manager will also determine whether you have any other software your program depends upon to run correctly. This automatic satisfying of dependencies can save you a lot of time when installing new programs.

Following are some of the most common package management programs:

• Red Hat Package Manager (RPM): RPM is perhaps the best known package management program. For more, see In Linux, what is RPM, and how do I use it to install software?
  
  
• Advanced Packaging Tool (APT): Initially developed for use on Debian GNU/Linux, APT has since been adapted to work with many other distributions (e.g., Solaris, Mandrake, Red Hat, SuSE, and Yellow Dog Linux). For more, see the APT HOWTO in the Debian User's Manual. Additionally, the manual pages for APT may be available on your system. To view them, enter: man apt
• Portage: Designed for Gentoo Linux, Portage offers functionality similar to that of the package management systems discussed above. Additionally, Portage is the primary distribution system for Gentoo Linux software. For more, see the Gentoo Documentation Resources page.

  The emerge command provides a command line interface to Portage. To view the manual pages for emerge, enter:

  man emerge

Availability

Note: Indiana University has a site license covering the use of Red Hat Enterprise Linux (RHEL) by students, faculty, and staff at IU. For details, see IU's software agreement with Red Hat.

Obtaining Linux on CD-ROM

You can find Linux CD-ROMs with printed manuals in many bookstores (including online bookstores).

Some of the boxed distributions commercial vendors produce come with additional email or phone support services available only to customers who purchase their official CD-ROM packages.

For a very low price, you can also purchase CD-ROMs without any printed manuals or support. For more, see the Linux Central or Cheap Bytes web sites.

Obtaining Linux on the Internet

Many distributors offer free Linux downloads from their web pages. In addition, many Linux distributions are available for download from the ibiblio Linux archive. Each separate subdirectory at this location contains the files of a different Linux distribution. In some cases, older releases of the distribution are available, as well as extra software such as "power tools".

Note: Some of the older, less prominent distributions available from the ibiblio Linux archive are no longer up to date with regard to the latest kernel releases or known security problems.

At Indiana University, University Information Technology Services (UITS) offers Red Hat, SuSE, and Ubuntu for download via IUware for Linux. UITS also mirrors several distributions, the entire Linux Documentation Project, and scripts and configuration advice relevant to the IU community at:

If you want only the Linux kernel itself, not an entire distribution, see the Linux Kernel Archives home page.

Support at IU

At Indiana University, for personal or departmental Linux or Unix systems support, see At IU, how do I get support for Linux or Unix?

Online documentation

An extensive and growing body of Linux documentation is available online via the Linux Documentation Project, which includes guides, FAQs, security information, manual pages, links to software development projects and software distributors, and online copies of numerous Linux manuals.