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What is meant by a “Linux distribution?”
January 28, 2008

Using different Linux distributions is analogous to driving different brands of automobiles. There are certain core similarities between automobiles, such as having four wheels, front wheel steering controlled by a steering wheel, brakes operated by a single pedal, and a throttle controlled by a second pedal mounted to the right of the brake pedal. There are dozens, if not hundreds, of these core features, many of which are standardized by law and some merely by historical precedent.

Tux the Penguin is the official Linux mascot. Source: Larry Ewing.

Similarly, there are core requirements for any operating system, such as managing system resources, which are standardized to make a Linux operating system a Linux operating system. These functions are implemented in a body of source code called the “Linux kernel,” which was started in 1991 by Linus Torvalds. Torvalds recruited a small army of other programmers to aid the project on a volunteer basis. The present version (2.6) was released in 2006. At the time of this writing, the “latest stable version” is 2.6.23.14, which was released two weeks ago (1/18/08). Version 2.6 is actually pretty robust, having been around since 2003.

Just as there’s a whole lot more to an automobile than a steering wheel, throttle pedal and brake pedal, there’s a whole lot more to a Linux operating system than the kernel, and that is mainly where one distribution differs from another. The desktop environment, for example, can vary widely. Different distributions include different utilities to provide the services needed for a complete, functional desktop computer operating system (OS).

Because Linux is open-source software, the numbers of programmers creating modules and programs for use with it is enormous. Some of these are available for free, while others are proprietary.

The difference between one distribution and the next comes down to what the distributor chose to include beyond the Linux kernel, and whether the distributor chose to modify the kernel. Usually, the distribution is optimized for a specific application. Wind River, Montavista, and others have assembled distributions with kernels modified for real time operation. Others, including Novell, Ubuntu, and Xandros provide distributions aimed at desktop computers. Many others have created their own specialized Linux-derived operating systems in a process called “roll your own” Linux. Each of these variants is a Linux distribution.

So, if you are considering booting up Linux on your home computer, or any other computer for that matter, you must first think about what you want to do with it and why. You should also think about what your computer skill set is and how much responsibility you want to take for your software system.

For example, Xandros Linux is specifically intended for newbies migrating from Microsoft Windows. Red Hat Enterprise Linux is for IT managers responsible for enterprise-level networks. There are tiny bare-bones distributions for those building embedded systems. Which fits your needs depends on what those needs are.

For more information visit the Control Engineering home page and search on “Linux.”

Posted by Charlie Masi on January 28, 2008 | Comments (0)