2. Linux.

2.1 What is Linux?

The primary author of Linux is Linus Torvalds. Since his original versions, it has been improved by countless numbers of people. It is a clone, written entirely from scratch, of the UNIX operating system. One of the more interesting facts about Linux is that development occurs simultaneously around the world.

Linux has been copyrighted under the terms of the GNU General Public License (GPL). This is a license written by the Free Software Foundation (FSF) that is designed to prevent people from restricting the distribution of software. In brief, it says that although money can be charged for a copy, the person who received the copy can not be prevented from giving it away for free. It also means that the source code must be available. This is useful for programmers. Anybody can modify Linux and even distribute his/her modifications, provided that they keep the code under the same copyright.

2.2 What makes Linux different?

Why work on Linux? Linux is generally cheaper (or at least no more expensive) than other operating systems and is frequently less problematic than many commercial systems. But what makes Linux different is not its price (after all, why would anyone want an OS -even if it is free- if it is not good enough?) but its outstanding capabilities:

• Linux is a true 32-bit multitasking Operating System, robust and capable enough to be used from universities to large corporations.
• It runs from low-end 386 boxes to massive ultra-parallel machines in research centres.
• There are out-of-the-box available versions for Intel/Sparc/Alpha architectures, and experimental support for Power PC and embedded systems among others (SGI, Ultra Sparc, AP1000+, Strong ARM, MIPS R3000/R4000...)
• Finally, when coming to networking, Linux is the choice. Not only because networking is tightly integrated with the O.S. itself and a plethora of applications is freely available, but for the robustness under heavy load that can only be achieved after years of debugging and testing in an Open Source project.