21 Jan 07
For those of you who don't know exactly what Linux is, I'll provide a short introduction. If you already have some experience with Linux or just want to get started, you may safely skip this section.
I don't want to insult anyone's intelligence, but I want to start at the beginning, with operating systems. An operating system (OS) is a large collection of programs that make your computer work. Windows is undoubtedly the most popular operating system in the world, but it isn't the only one available. Mac OS, which runs on Macintosh computers, is another example. Unix is another example, popular in the world of servers and computer engineers. In simplest terms, Linux is an open-source version of Unix.
Linux is a free operating system that is designed to be secure, powerful, and flexible. Free means a few different things for software. First, it doesn't cost money. You can download Linux and install it on your computer without paying anyone anything. It also means that it is open-source. “Open source” means that everyone has access to the underlying code used to build the operating system and is allowed to make changes to that code.
Open-source has several advantages. The first is that you can modify your OS and make your computer work any way you want. Another advantage is that you can see exactly what your OS is doing, so that you can be confident that there aren't any backdoors, security holes, or bugs left in the code. In contrast, Windows is closed source, so you can't modify the code and you can never be sure of exactly how everything works.
The Linux kernel was written by Linus Torvalds in 1991. Linus wrote Linux to be completely compatible with Unix. Programs written for Unix almost always run in Linux without any modification, and vice-a-versa. Most of the commands work in the same way on both operating systems. The difference between Unix and Linux is that Linux is released under the GPL license while Unix is usually covered by a BSD-style license. The biggest difference between the two is that you a BSD-style license lets you do pretty much anything you want, while GPL requires you to release any changes you make to the code and redistribute under the GPL as well. This ensures that everyone continues to benifit from the improved code.
The kernel is bare bones of the operating system. Linus combined his kernel with software from the Free Software Foundation's GNU project, which was started by Roger Stallman in the mid 1980's. The command shell, C program compiler, and other programs made Linux a complete and very useful operating system. The Linux kernel and most of the software in the GNU project are still in active development and continue to improve in quality and functionality to this day.
Linux has grown into a very mature operating system that functions well for everything from a desktop surfing the internet and writing documents to running a mail server servicing thousands of customers. There are now hundreds of different distributions of Linux and millions of people using it everyday, using it for everything from running a movie theater to driving a solar-powered car and flying the space shuttle. Even the popular TiVo runs on Linux code.
28 Jan 08