If you have even a casual interest in computers, then the chances are you've heard of Linux. Linux, like Windows and Mac OS X, is an operating system. Without getting too technical, the operating system (OS) is the platform on which everything you do on the computer sits. The OS manages all the physical components of a computer so that the programs you use (like a word processor) can function. It also acts as a ringmaster so that multiple programs can function together. For example if you are browsing the web and simultaneously listening to music on the computer, the OS is busy making sure that both your browser and your media player have the resources they need and that neither is encroaching on the other's space.
Linux has been around for some time (since 1991). For many years it was only suitable for use by enthusiasts willing to spend a lot of time learning how it worked. However in recent years it has become sufficiently mainstream that Dell and others will sell you a PC with Linux installed instead of Windows. So what are the benefits of Linux and why should you be interested? Three words provide the answer: cost, security and freedom.
Cost:
Windows (and for that matter Mac OS X) isn't free just because it was included with your current computer. Whenever you buy a new computer which comes with Windows, the price you pay includes a payment to Microsoft for Windows. In fact the Windows software license says that you can get a refund for the cost of Windows if you choose not to use a copy that comes with the computer. Buying a shrink-wrapped copy of Windows makes the cost explicit. If you want to upgrade your operating system without getting a new computer at the same time, an upgrade version of Windows Vista can cost up to $259. In contrast Linux is available from many sources for free. One supplier (Ubuntu) will even send you multiple copies of their installation CD, postage free, so that you can also give copies to your family and friends. Even better, virtually all the software available for Linux is also free, from office software which can read and save Microsoft Office formats to graphics programs to multimedia players.
Security:
Although undoubtedly more secure than it once was, Windows is still beset by malicious software like viruses and spyware which flourish in the wild places of the web and on compromised home computers. Some of these nasties are even capable of infecting Windows systems running up to date virus checkers. Linux by contrast has no extant viruses "in the wild". Although a few have been created, none have ever become established. The structure and working practices of Linux makes it difficult for automated malware to infect. An illustration of Linux's more secure approach is the way in which Linux users typically obtain new software. An up to date version of almost all significant software for Linux is provided by central repositories which are set up for particular flavours of Linux (of which there are many). Getting software from these repositories ensures that it is not infected by anything untoward and users are not required to judge whether individual websites offering software are trustworthy or not. A vivid illustration of the current threat level for Linux is that Linux users typically do not run virus checkers.
Freedom (AKA choice)
The freedom benefits from running Linux are more subtle, but over time significant. At the root of this freedom is the open source philosophy on which Linux rests. Open source (for software) means that the computer code which makes up the programs you run is available for anyone to look at, comment on and improve. Anyone interested in tinkering is free to alter the majority of Linux programs to suit their needs (although this is an entirely optional pursuit and not at all required to use Linux).
This freedom results in several benefits. Amongst other things it means software that doesn't try and lock you in to proprietary formats in order to tie you to a particular software vendor. If you find a new Linux program more suited to your needs, it is very likely to work with your existing files. It also means lots of choice when it comes to getting things done, from which you can pick what suits you best. For example there are many variations of Linux (known as distributions), each with a different target audience. Some are intended strictly for Linux veterans while others cater to new and beginning users by simplifying the Linux experience from installation to everyday use.
What if I want to learn more?
As a potential new Linux user check out the websites of Ubuntu, PCLinuxOS and Freespire to see if any of these versions of Linux appeal to you. Ubuntu in particular has proven very popular with people new to Linux and offers a "Live" cd from which you can try Linux without making any permanent changes to your computer.