From the outside it's just another unprepossessing North London warehouse, but it is here that a small part of the struggle between the worlds of Linux and Microsoft can be seen at first hand.

The building belongs to Computer Aid International (CAI), founded in 1998, and a registered charity dedicated to refurbishing discarded PCs for use in schools and community organisations in the developing world, mostly sub-Saharan Africa, Latin America, and parts of Asia.

Several times a week, trucks arrive from all over London and the UK, disgorging their cargo of unwanted metal boxes into a cargo bay from where they are stacked from floor to ceiling until the staff have almost no space to move.

As well as various generations of PCs, there are laser printers, oddly new-looking inkjets, an army of keyboards and mice, in fact every kind of PC peripheral imaginable. CAI turns nothing away if it can help it.

The only thing that is guaranteed is that the hardware will not be this year's model. Washing machines soldier on until they break down, as do most dishwashers, TVs, and motor cars. But not PCs. Once they have been depreciated by accountants, or simply replaced because something bigger and faster is available, they are usually chucked out the back door for a trip to the local landfill.

Computer Aid International recently refurbished its 30,000th PC, and is seeing the supply of PCs increase at 100 per cent per annum. That's a tiny number when set against the CAI's estimate of three million PCs decommissioned each year in the UK. According to CAI, less than 15 per cent of this total can be confirmed as having been recycled or reused.

Now a few from this mountain of old hardware end up here, ready to be given an unexpected second life.

A recent EU move – the waste electrical and electronic equipment (WEEE) directive – will from this month set tough new targets for the recycling of IT equipment in member states, so the supply of PCs into CAI's warehouse could be about to increase dramatically.

Near the cargo bay is the real museum. ZX-81s, old XT-class PCs, circa 1981, Mac SEs and various other long-defunct bits and bobs such as the 1980s classic, the BBC B. Once these might have found homes in an African school, but these days expectations are set much higher.

The worthy story is that old computer hardware is being put to good use, and helping raise up part of the world where money for new computers is in short supply. Then you enter the bay where volunteer technicians busy themselves loading software on to the hard disks of those PCs that have made the grade, using an set of automated routines. Increasingly, that software is Linux.

Computer Aid's chief executive Tony Roberts reckons that 10 per cent of the machines that leave CAI end up with GNU Linux installed leaving 90 percent that presumably end up running Windows. At the moment, CAI ships all its PCs bare-bones – the recipients add their own software according to preference.

Despite its reputation for adding licence cost, in the case of charitable recycling Microsoft has for some time levied only $5 per machine to those organisations such as CAI, as long as they qualify as licensed "Microsoft authorised refurbish scheme (MARS) providers" and are supplying non-profit or education organisations (applications still cost so this could be seen as a subsidy of sorts). CAI has applied for this status and will in future install Microsoft software where it is requested. Regardless of OS, CAI levies £39 plus shipping for each refurbished PC to cover its costs and then adds shipping charges, so the machines are not free to recipients even when they have Linux installed.

Nevertheless, an increasing number of partners in the developing world are choosing free and open source software, slowly eating into Microsoft's traditional dominance in these regions. Cost is turning out to be only one of the issues.

There's nothing new in the idea that the developing world will increasingly use Open Source software – China, India, Japan, and others have made noises to that effects for some time. But more recently African countries including Nigeria, Namibia and, further afield, Peru have indicated they plan to move from 'proprietary' systems such as Microsoft to open source for government and public sector software procurement. In a realm where Microsoft once ruled it can no longer take sales for granted.

The world is hungry for computing power at a time when software is becoming increasingly political. There is a belief that proprietary systems lead to dependence on imported technology and skill where countries would rather develop their own.

"If there is an viable alternative which obviates the above ruinous costs and lock-in to a proprietary monopoly - underdeveloped economies are compelled to give it serious consideration," comments CAI's Roberts, expressing a personal rather than organisational view.

Southern hope
South Africa is the most developed economy in Africa and offers a test example of how the software head-to-head might develop in the coming years. Denis Brandjes runs Direqlearn , a private company selling thin client and open source software to the country's education sector. The company makes a speciality of using refurbished hardware, and takes machines from CAI in London.

With a background in the non-profit sector and a business selling open source systems, Brandjes admits that ideological opposition to Microsoft's hegemony is important. "There is a philosophical motive with many non-profits. They're not selling their souls to an entity in Redmond," he says. "It [Microsoft's] is an embedded dominance, it's what people have known since IT began."

The now-refurbished PC would have had a paid-for copy of Windows installed on it when it was first sold so why should companies recycling it have to pay again, he asks.

A 20-PC network based on refurbished systems and his company's Linux-based educational package sells for the Rand currency equivalent of £8,300, as compared with £11,500 for the same system using new PCs. He estimates that an identical Microsoft-based system based on new PCs – but minus the educational content his company adds - would cost almost £15,000.

He argues that refurbished PCs running Linux on either desktops or servers, still offer the best cost-performance for the specific requirements of education, despite their lower performance. He favours thin client systems because they avoid the problem that many of the aged refurbished PCs struggle to run today's desktop software, and require less support. But he stresses that "it's not just about technology, it's about educational outcomes."

What about targeting the business sector where Microsoft still dominates? Brandjes sees a large business opportunity in small and medium-sized companies and raises the possibility of investing in a spin-off company to target Linux systems at this sector.
Figures on the extent to which Linux is eating into Microsoft's market share are hard to come by for Africa and the developing world as a whole but anecdotal evidence suggests it is slowly losing, and will continue to lose, market share. Apart from upfront cost, political opposition to a large US-based company is another reason. The fact that recycled PCs are set to become even more plentiful will serve to amplify such factors.

Microsoft is fighting back, offering better deals on software licensing through its local partners, aware that its dominance can't be assumed in the long run. For the time being, it is being partly protected by the economics of PC ownership. New PCs come with Windows pre-installed and the number of refurbished PCs is still tiny relative to sales. The capital cost of new PC hardware has also nearly halved in the last two years, making recycled machines harder to shift at any cost.

But Linux's biggest enemy in its attempt to use refurbished PCs as a back-door challenge, is not Microsoft or any or its partners. Paradoxically for a movement born out of free and open source principles, it could be software pirating.

Currently, Computer Aid International's refurbished PCs leave the UK without an operating system of any sort. What happens to them? Brandjes reckons many of them probably end up using Windows but pirated versions of Windows. This is a loss to Microsoft, obviously, but also undermines its rivals. The mostly young users of these systems spend their formative years using Microsoft's products not those of Linux, reinforcing its long-term dominance.

"In the poorest countries on the planet some donated computers end up using unlicensed proprietary software for want of funds. If the computer is in a health centre in Burundi dealing with the HIV/AIDS pandemic, someone inevitably has to divide and allocate scarce financial resources between various potential expenditures including software licences or medical supplies," says Roberts of CAI.

Nevertheless, software pirating works with the status quo because that is where convenience, necessity and sometimes profit are best served. The fact that Linux has no licence cost is irrelevant if the value of software is measure relative to its official price. Linux could take years to overturn this entrenched view.