A competitive market, in which a number of producers offer a variety of similar products that all have their own unique selling points, is good for consumers. That's because producers gain customers only by tailoring products to match consumers' demands. Or put another way, consumers can look at a selection of competing products and choose the one that's best for them. Innovation by one producer is followed by others' imitations, so over time the overall quality of all the product offerings improves.

A monopoly, as we all know, has a single producer that controls the market, and consumers are grateful for whatever they are offered, at whatever price the monopolist decides he or she can get away with.

When you look at the operating systems markets, it's pretty clear that the market for Linux is a competitive one. There are dozens of desktop Linux distros, and a good number of server ones, too. Red Hat and Novell have a large share of the enterprise market, but there are others, such as Ubuntu Server, with their own unique selling propositions to attract customers. To add spice to the competition, the paid-for distros (which get revenue from customers through subscriptions) are also competing with distros that companies may use without paying a cent. That means there's a very big incentive for companies like Red Hat and Novell to ensure their offerings (e.g., the distro, support services, patches and pricing) are as attractive as they can be to compete with "free," and Linux users can be pretty much assured of finding a good solution somewhere. The same goes for some flavours of Unix, as well.

But don't take my word for it. Linus Torvalds himself, talking to DistroWatch Weekly at Linux.conf.au last month, brought up this point. "I think multiple distributions aren't just a good thing, I think it's something absolutely required. We have hundreds of distros, and a lot of them are really for niche markets. And you need that — simply because different markets simply have different requirements, and no single distro will take care of them all," he said. Sure, Torvalds was talking principally about desktop distros, but his comments apply equally to servers versions as well. "In addition, having multiple players just keeps everybody honest and allows you to compare them. It may all look a bit messy and complex, but I'd much rather have a multi-party system over a single-party one. Even if it's more complicated."

Let's contrast that with the Windows OS market. It looks like a monopoly. On the desktop side there's Windows Vista, offered by a single producer, Microsoft. Of course, Vista is offered in a number of different variants (e.g., Business, Ultimate and Enterprise). You can argue that by offering variants, Microsoft is not forcing customers to buy features they don't need, but you can equally argue that the company is forcing customers to pay whatever it asks for the features they do need. Either way, the variants are just that — variants of the same single product, not different products in and of themselves.

Still, at least customers have a choice of variants. Poor OS X users get no choice at all. Apple decides what they want, and they have no option but to take it. In the words of the poet and songwriter Gil Scott-Heron: "When the producer names the tune, the consumer has got to dance. That's the way it is."

The server operating systems market is actually a slightly more complex market than I have just described. Neither Microsoft nor Apple are truly monopolists — they are competitors in a larger operating system market. On the server side, Windows has the dominant market share, Unix is huge but losing ground, Linux is still small but making gains, and OS X fails to register.

The interesting thing is that Linux's market share, although small, is growing the fastest. It may turn out that the competition between Linux distributions is what sustains this growth, ensuring Linux as a whole becomes more attractive year by year. If so, it will ensure customers' needs are met very precisely through a variety of different distributions. Because, as Linus puts it, "no single distro will take care of them all." Microsoft and Apple, take note.

Footnote: All this talk of competition among Linux distros begs a very obvious question: What distro does Linus use? The answer, apparently, is Fedora. "One of the reasons I like using Fedora is that I know that they are particularly active in both having developers and in trying to also track the latest kernel fairly closely and be actively involved with bug reporting," he explained.

Paul Rubens is an IT consultant and journalist based in Marlow on Thames, England. He has been programming, tinkering and generally sitting in front of computer screens since his first encounter with a DEC PDP-11 in 1979.

This column appeared originally on ServerWatch.com.