Linux

Last updated: June 12, 2007.

Could a bunch of ordinary people get together to design and build a space rocket that would take them to the moon? It sounds like a crazy idea, doesn't it? How could amateurs possibly cooperate to pull off something so intricate and complex? A few years ago, if you'd suggested thousands of amateurs could work together to build a rival to Microsoft's mighty Windows operating system, people would have thought you crazy too. But that's exactly what's happened with Linux, a freely available alternative to Windows developed mostly by brilliant young computer programmers in their spare time. Let's take a closer look at the miracle of Linux!

Photo: This penguin, nicknamed Tux, is the mascot of the Linux operating system.

What is an operating system?

Most people don't think too much about how their computers work. They just click on the desktop icons and run the email program, word processor, Web browser, or MP3 player. It doesn't matter how the computer does what it's doing; all they care about is that it helps them send an email, write a letter, do a Google Web search, or download a song. Programs that run on our computers doing useful jobs like this are called applications (or application programs)—but they're only part of the story. Underneath the applications, there's a more basic program running that helps all the applications to do their work. It's called the operating system.

The operating system's job is manage all the computer's basic operations, by doing things like displaying characters on the screen, figuring out which keys you're pressing on the keyboard, turning on the fan when the processor chip in your computer gets too hot, and storing data (information) on the hard drive. Because the operating system worries about all these mundane chores, the applications don't have to: they can simply concentrate on the jobs they have to do. If there were no operating system, every application program would have to do all these things too—which would be a huge duplicated effort.

Think of a computer as an office block where all the people inside are journalists busily putting together a newspaper. The journalists are trained to gather and publish news; they don't want to have to worry about running the canteen, hiring security guards, cleaning the windows and so on. So they employ (or "contract out") these basic jobs to another company that specializes in what's known as "facilities management" (looking after the building). An operating system is just like facilities management: it does the dirty jobs for application programs so they can concentrate on the more interesting stuff that they're really good at.

The rise of Windows

Windows (and its predecessor DOS, Disk Operating System) became the world's favorite operating system in the early 1980s. Before that time, small personal computers (which were then known as microcomputers or micros) had no operating system. Each machine worked in its own unique way. If you wanted a really good arcade game for your computer, often you had to write it yourself. And, because there was no operating system, you had to write it in machine language—the raw code of the computer's processor. Even if you were developing a game, you had to know how to make characters appear on the screen, operate the disk drive, and do all that other nitty gritty as well. Because each computer worked differently, programs written on one machine wouldn't work on anything else. Every machine was totally different and it was a nightmare to get machines to talk to one another or exchange information.

An early operating system called CP/M changed all that. Once microcomputers started to use CP/M, they could suddenly all use the same programs. The idea was simple. The companies who made the computers ensured that they could run the CP/M operating system. Once they'd achieved that, their machines could run any and every program already written for CP/M—the programs didn't need to be rewritten, as they would have had to have been if CP/M hadn't existed.

When IBM launched its hugely popular personal computer in the early 1980s, it tried to buy the rights to CP/M—and failed. Instead, it arranged for an unknown boy-genius programmer to write an alternative operating system of its own: DOS. The boy genius was Bill Gates and DOS gradually evolved into Windows, a product so successful that it made Gates the world's richest man. The great thing about Windows was that it made the world's personal computers talk the same language, so it was suddenly possible for different machines to run the same programs and exchange information very easily. People often say that ever-shrinking, ever-more-powerful microchips caused the computer revolution—but the success of Windows in making computers more uniform, compatible, and easy-to-use was hugely important too. You can read more about this in our article on the history of computers.

Photo: Spot the difference! To a computer user, a Windows system (left) and Linux system (right) look virtually identical and work in a similar way. You can customize the way your Linux desktop appears to make it look virtually identical to Windows, if you wish. Once your Linux system is up and running, it's as easy to use as Windows and you won't notice the difference.

From Windows to GNU/Linux

If Windows is so good, why would anyone want an alternative? Many people—especially more technically savvy ones—don't like certain aspects of Windows and the Microsoft "culture" that goes with it. They don't like Microsoft's domination of the computer industry and the strong-arm tactics it has allegedly sometimes used against its competitors. They don't even think Windows is a particularly good product. One obvious risk is that if everyone uses the same software, harmful programs like computer viruses and "worms" can spread more easily. Apart from that, not everyone agrees that we should all do things the same way. Henry Ford once reputedly said to his customers that they could have his famously successful Model-T in any color, "so long as it's black." Some people just like to do things differently.

Linus Torvalds is one of those people. During the 1990s, this Finnish computer programming student thought he'd have a go at writing his own operating system, loosely based on a well-known system called UNIX. He shut himself away in a bedroom in his mother's house, lived off her pasta, and eventually posted a message on an Internet bulletin board telling the world what he was up to: "I'm doing a (free) operating system (just a hobby, won't be big and professional...)" Soon, thousands of other amateur programmers had joined in the effort—and the Linux operating system was born. The core of Linux is a basic operating system called the kernel. On top of this, people run applications written for the Linux kernel, many of them also developed by amateur programmers. This collective of people who write "free software" was originally inspired by another maverick programmer, Richard Stallman, and a project he started named GNU. Now, more than a decade later, GNU/Linux is such a credible alternative to Windows that companies like IBM and Dell are shipping it on their machines. Linux may not have started out "big and professional", but it's quickly ended up that way.

Linux in practice

When people talk about Linux, they are often referring loosely to both the operating system kernel and the applications that run on top of it. Indeed, if you decide you want to run Linux on your computer, you usually get it from what's called a distribution or "distro". This is typically a set of CD-ROMs or DVDs that installs onto your computer the basic operating system kernel and a huge collection of application programs.

So what's Linux like in practice and how do you get started with it? I'm writing this article now using a version of Linux distributed by a German company called Suse. When I bought my laptop, I bought a Suse Linux package at the same time: a set of several CDs and a manual. To get Linux working, I simply inserted the CDs into the drive and booted (started up) the machine. The Suse Linux installation program partitioned my hard drive (split it into two) and moved Windows to one side in one partition. In the other partition, it installed the Linux kernel and dozens of free application programs. For virtually every program you can think of that runs on Windows, you can find a similar equivalent that will run on Linux. Thus, there's a comprehensive office suite called OpenOffice that runs a word-processor, spreadsheet, and slideshow that are almost completely compatible with Microsoft's Word, Excel, and Powerpoint. There's the Mozilla web browser for sending emails and surfing the Net. There's an MP3 player called XMMS and a movie player called Kaffeine. There's even a complete graphics program called The Gimp. Windows is still on my computer too and runs just like it always did in the other partition; I simply choose which system I want to use when I boot my machine. An arrangement like this is called dual-booting, because I can make the computer start in Windows or Linux, as I wish. I now have two machines for the price of one!

It all sounds easy—but there are some drawbacks. Setting up Linux to start with can be a simple, half-hour task—or it can have you tearing your hair out for days and weeks if your system is unusual. One of the biggest problems is that Linux isn't nearly so comprehensive as Windows in the way it handles peripherals (the add-ons like USB modems and inkjet printers that you plug into your machine). Even if you have a perfectly ordinary printer or scanner, you might find that Linux doesn't support it: it might not have a small program called a driver that tells your computer how to use it. In practice, there are three solutions to this. Either you can wait until one of those helpful amateur programmers sorts out the problem and modifies the Linux kernel or writes a driver so it does what you need, or you can buy replacement peripherals that Linux does support, or you can run Windows each time you want to use that troublesome bit of kit.

Why bother with Linux? There are no viruses, worms, or security scares to worry about. It typically runs faster than Windows. And it's mostly "free" in both senses of the word: programs written for Linux are copyright free, so you can share them easily, and they are often given away at little or no cost. You can get an entire Linux distribution, with the kernel and all the programs you need, for an outlay of just a few dollars or pounds. Compare that to the price of Windows, and all the expensive software that comes with it, and you'll see what an amazing deal Linux really is.