Introduction to Linux

What is Linux

In 1991, Linus Torvalds, wanting experience with programming on the 386 chip, and having had experience with the Unix operating system at university, started writing what was to become the Linux kernel.

Since then, more than 250 developers have contributed directly to the kernel, untold thousands have written applictions, and millions of people have been running Linux every day, providing valuable testing. This makes Linux powerful, robust and stable. It supports several different architectures, runs well as a server, workstation, or development machine.

Linux is distributed under a free license (free as in political freedom, not cost): the GNU GPL (General Public License). Anyone is allowed to download and modify the source as they see fit; usually patches are contributed back to the original maintainers through goodwill and a strong sense of cooperation.

This license was created by Richard Stallman, as part of the GNU Project. Software written for the project is a fundamental part of Linux, as many of the tools, such as the compiler (gcc), a very popular editor (emacs), and the system librares (glibc) were created by GNU.

How has it changed

Linux has undergone radical changes since its inception. It has support for almost all hardware that is readily available (printers, CD-ROM drives, video cards), as well as more obscure hardware (radio tuners, tv cards, 3D accelerator cards, Universal Serial Bus (USB)). Even the mainstream press has started taking note.

Recent announcements of support have come from Netscape, Oracle, Informix, IBM, and many others. Some of them have invested in Redhat, some have ported products to Linux, some have yet to contribute, but support has been widespread.

There are many Open Source (and commercial) products available for Linux: word processors, high-quality graphic manipulation tools, compilers, games, and email and web clients. Almost any software that exists on other platforms has an implementation or similar (if not superior) product available that will run under Linux.

The level of technical support for Linux, both commercial and free, has increased dramatically. There is documentation written by people all around the world (and consequently in many languages); there are mailing lists, newsgroups and websites ready to answer any question about Linux; there are Linux User Groups in most large populated areas providing a high level of support to veteran and new users alike.


The basis of Linux is the kernel. It evolves in two streams, stable and development. Kernel versions take the form `x.y.z': when y is even, the kernel is a stable version, when y, is odd it is an `unstable' version with more features.

The kernel is currently at version 2.2.9 (released on May 13, 1999), the development stream has just been released and is at version 2.3.3 (released on the same day). As the kernel develops independently of nearly all the application software available, upgrading has become much less error-prone and dangerous than the early days.

History of Kernel

1991 - Linux 0.02 released
March 1994 - Linux 1.0 released
Stable on x86
March 1995 - Linux 1.2 released
Device driver enhancement, start of port to other architechures
June 1996 - Linux 2.0 released
Stable multi-architecture - x86, alpha and others
Firewall, ip masq, inital SMP, kernel reworked to support multi-architechure
January 25, 1999 - Linux 2.2 released
Better support for the variety of intel-like chips - ie AMD, Cyrix, Celeron, PII, etc
Much improved SMP support
Frame buffer console support
Filesystems - much improved range - including all MS filesystems, Solaris, BSD, etc
Raid support much improved
New firewalling code - ipchains
Improved networking code - start of IPv6, etc

The Different Types of Linux


Linux comes in many different formats, called distributions. These are the linux kernel, packaged with many tools, including a GUI called X Windows, which is standard among Unix installations the world over. The main difference is package management---this includes how programs are installed version control.

Linux has recently been making large improvements recently by adding desktop systems to X Windows: KDE, and Gnome. KDE is a fully intergrated system, including a window manager, and many useful applications. Gnome is a system which exists alongside the window manager, allowing configurability. These, along with the plethora of applications that have been written, are drawing attention from desktop computer users.

Caldera OpenLinux
Debian GNU/Linux
Linux Mandrake
RedHat Linux
Slackware Linux
Stampede Linux
S.u.S.E. Linux
Yggdrasil Linux


As mentioned before, Linux has been ported to many different platforms, ranging from i386, to Silicon Graphic workstations.

ARM Linux
Linux / DEC Alpha
Linux for DECstations
Linux CE
ELKS: Embedded Linux Kernel Subset
Linux / m68k (Atari and Amiga)
Linux / m68k (Macintosh 68k)
Linux / MIPS
Linux for Power Macintosh (MkLinux)
MCA Linux
Linux / Microcontroller
Linux / SGI (Silicon Graphics)
Linux for SPARC Processors (S/Linux)
Linux / sun3
VAXlinux Project


Linux has progressed quite a bit. It has gone from a learning experience to an idea that has captured the attention of many. Whatever the future may hold, you can be sure that it is bright.