1. Introduction

The Linux operating system is an extremely versatile Unix-like operating system, and has taken a clear lead in the high performance and scientific computing community. Nearly 92% of the computers found on the Top500 list run some type of Linux or Unix operating system.

Linux is a multi-user, preemptive, multitasking operating system which provides a number of facilities including management of hardware resources, directories and file systems, and the loading and execution of programs. There are several flavors of Linux and Unix, each with subtle differences, which were created by vendors for their specific hardware. Some examples include Solaris (Sun), AIX (IBM), IRIX (SGI), System V (AT&T), and BSD (Berkeley). This tutorial will discuss the "vanilla" flavor of Linux; it will not discuss any of the specific subtle differences from other versions of Unix or Linux.

History

The Unix operating system got it's start in 1969 at Bell Laboratories and was written in assembly language. In 1973 Thompson and Ritchie succeeded in rewriting Unix in their new language C. This was quite an audacious move; at the time, system programming was done in assembler in order to extract maximum performance from the hardware; the concept of a portable operating system was barely a gleam in anyone's eye.

The creation of a portable operating system was very significant in the computing industry, but then came the problem of licensing each type of Unix. Richard Stallman, an American software freedom activist and programmer recognized a need for open source solutions and launched the GNU project in 1983, later founding the Free Software Foundation. In September of 1991 Linus Torvalds released the first version (0.1) of what was to become the Linux kernel. Torvalds greatly enhanced the open source community by releasing his licensed under the GNU license so that everyone has access to the source code and can freely make modifications to it.

Why Linux?

Linux, an open source version of Unix, has been so heavily utilized in the high performance and scientific computing communities that it has become the de facto standard in many areas of academic and scientific research, particularly those requiring high-performance computing. There have been over 40 years of development in Unix (and later Linux), with many academic, scientific, and system tools. Linux has four essential properties which make it an excellent operating system for the science community: performance, functionality, flexibility, andportability. Performance of the operating system can be optimized for specific tasks such as running small portable devices or large supercomputers. A number of community driven scientific applications and libraries have been developed under Linux such as molecular dynamics, linear algebra, and fast-Fourier transforms. The system is flexible enough to allow users to build applications with a wide array of support tools such as compilers, scientific libraries, debuggers, and network monitors.