What is Linux?

A lot of myth and misunderstanding seems to surround Linux and other Unix derivatives, especially amongst those who have never tangled with any of them before — such unfortunate folk tend typically to come from Microsoft backgrounds, but from time to time we find others too. Here we shall try to dispel some of the myth and to explain why Linux is a strong contender for corporate use.

Linux is a variation of the Unix operating system. Unix was developed at the Computer Science Research Group of AT&T Bell Laboratories during the 1970s and is popular in academic and commercial environments because of its elegance, simplicity and the intellectual rigour that has gone into its development. It is portable — i.e. runs on many different computer types (from desktops up to mainframes) and is widely used for heavyweight computing in large companies. It is also the backbone of the Internet; some 80-90% or so of all the web servers in use on the public Internet are Unix-based, as are the systems that carry the electronic mail. Unix is famous for its reliability and the frugal way that it uses resources. Commercially supported Unix systems are provided by all of the large computer companies such as IBM, Hewlett-Packard, Sun Microsystems, Digital (now Compaq), Silicon Graphics and others.

One common misperception of Unix is that there are `many different versions'. There is a grain of truth in it, but the reality is that the different versions of Unix are much more alike than they are different — a parallel can be drawn here with the many different versions of English: although there are clear differences between American, British, Australian and Caribbean dialects of English, if you speak one of them you can communicate with English speakers the world over. Similarly, if you are familiar with one dialect of Unix, you can use any Unix system you are likely to encounter without needing more than a moment or two of acclimatisation. Linux is simply another Unix, instantly recognisable to and usable by anyone who has used Unix before. Each of the large suppliers has ther own Unix derivative, with the similarities of each very much greater than their differences.

Unix has traditionally excelled in corporate applications for financial and database applications as well as very high-end graphics and computer-aided design applications. The fact that the general public tend not to see it in use tends to give it a low public profile, but it is a general workhorse of mid-to-large scale corporate use. Because of this, the various Unix vendors have typically gotten away with charging high licensing fees and Unix software has tended to be expensive.

Linux is very different from the corporate versions of Unix in a crucial way: it is developed according to the open source model of software production. In other words, it is a collaborative effort of thousands of developers all over the world, contributing their time and effort without recompense except for the knowledge that they have access to the results of the collaborative work (though most do it just because they enjoy it).

At first glance this may look like a recipe for muddle confusion and unpredictability, but as Eric Raymond has pointed out in a famous paper on the Bazaar method of software development, the results are surprising. Linux is just one instance of extraordinarly high-quality software produced by this method, winning hands-down on issues like reliability, security and support, when compared to for-profit corporate software development projects. Other examples of the technique at work include (there are many others too) the Sendmail project which produces the software used all over the world for Internet mail, the Apache web-server project which has produced the 'market-leading' web server (so good that IBM have chosen to use it in their commercial products) and the GNU family of tools and compilers. Anyone familiar with these products will vouch for the extremely high levels of quality and support that characterises them. When people talk of `Linux' systems, they are mostly referring to a whole bundle of software, including those just mentioned, which are commonly bundled together and called a Linux distribution.

Unlike big-company Unix versions, Linux is distributed according to the GNU public licence — in essence it is free of charge and may not be charged for (apart from added value features such as documentation, distribution media and support). This is a remarkable situation: what many knowledgable insiders recognise as the top-quality software is not only the lowest cost product, it is actually free! As a shorthand many refer to it as `free software' but unless you know what is meant by that term, it can be dangerously misleading.

The IS directors of large companies have a natural mistrust of anything described as `free', since this usually implies throwaway or giveaway quality too. Or put another way, rubbish. This is entirely understandable. It is very hard to defend the use of `free' software for important systems where real money can be lost. Making the case requires an intelligent audience with time to listen and that is very rare, especially if a serious problem has just occurred. Although fair bit of what is shipped with allegedly commercial, supported Unix systems is actually just the free stuff anyway, packaged along with the high-priced and badged Unix system from that vendor ... it comes with a name that creates a warm and trustworthy feeling makes the IS directors feel happy. Not surprisingly, the businesses that have chosen to use Linux as their standard computing environment seem to be thin on the ground.

A change is occurring now though. Evidence — anecdotal, it is true - is beginning to accumulate that whilst the IS directors have laid down a policy, the poor souls who have to implement it, those at the sharp end, are finding ways and means of introducing Linux systems surreptitiously. A few high-profile organisations (such as NASA and Boeing) have been happy to admit openly that they use Linux, but the majority don't even know it officially. Despite that there is now enough weight behind Linux in the corporate environment that Oracle, Corel, Informix and others have announced plans to make it a supported product. Grass-roots acceptance now means that at the corporate level, Linux has `come onto the radar screens'. For some the blip is clearly moving quickly.

So why is it becoming popular? Is it because of cost, or is for other reasons? In our opinion, cost is rarely the driving factor. Linux systems offer no competition to the current dominant desktop system, Windows in its various forms. The applications simply don't exist, (though that situation is changing). Linux comes into its own as a server system. It provides excellent compatibility with Windows/NT networking as well as Novell, but its greatest strength is its flexibility, its configurability and its legendary reliability. Systems administrators are generally averse to being called out of bed in the middle of the night; they hate flaky systems. Ask most what they think of NT and you get a dusty answer. Linux goes in and once configured it just runs for ever. A reboot or crash is talked about for days afterwards, it is such a rare event. In other words, Linux is liked because it is so good at what it does, and its total cost of ownership (discounting any initial cost of lack of it) is low.

Cost — or lack of it - is a secondary factor for many, but not simply because Linux is free. Responsible large companies have serious problems in tracking licence usage for software. They will pay - somtimes not without a wince - but they will pay for licences to use the software that they need. The problem is making sure that they have enough licences. When they find that this problem goes away with Linux they are doubly happy. Not only may they be saving thousands over the equivalent solution based on proprietary software, but they are also ridding themselves of the burden of worrying about one day being asked to prove that they are fully licensed.

Linux has already started to make itself known as a server system in many companies. At the moment it is mostly used for mail services, for file and print serving and as an intranet server. The availability of serious commercial databases will be an important next step on its path to acceptance as part of the overall corporate computing platform. We are watching developments with interest! We expect to see usage grow over the coming years. Our own experience of switching our systems to Linux has been one of great relief and pleasure.