IBM announced it will offer German Government offices deep discounts on computer systems based on Linux, rather than Microsoft's near-ubiquitous Windows operating system.

Germany's Interior Minister, Otto Schilly, said the move would help cut costs and improve security in the nation's computer networks.

"We are raising computer security by avoiding a monoculture, and we are lowering dependence on a single supplier," he said in a statement.

"And so we are a leader in creating more diversity in the computer field."

Neither the government nor IBM would disclose the terms of the agreement.

But a spokesman for SuSE, the German company supplying the version of Linux involved in the deal, said the deal was directed at the interior ministry, which oversees law enforcement in Germany.

Most of the computers in Germany's public sector run Windows.

Open and shut case

Germany is far from being the first country to turn to "open source" software as a means of securing its computer networks and saving money.

"Open source" means that the core of a program or an operating system is open to anyone to experiment and fix errors.

Linux is an open source variant of the 30-year-old Unix operating system, which is generally held to be almost indestructible and by far the most reliable core for computer systems for whom crashing is not an option.

While the software itself is free, companies such as SuSE can still charge for technical support and other services, such as bundling it with easy-to-use installers or extra software.

In proprietary software such as Microsoft's Windows, on the other hand, a single company controls the code, setting licensing terms for users but blocking outsiders from accessing the code.

Access all areas

Proponents of open source software for governments say the code is more bug-resistant and more secure - as well as saving huge amounts of money thanks to avoiding being locked into a single company's licensing fees.

They also say using open source ensures that data will be widely compatible, and not be dependent on users - whether staff or citizens - using the same proprietary software.

Microsoft, whose Windows operating system runs more than nine in every ten desktop machines around the world, is keen to keep its hegemony.

It says that switching to open source can damage a country's indigenous IT industry, because some varieties of open source software place restrictions on copyright and intellectual property.

It also says that it is a more reliable partner than smaller, less well-established open source distributors.

"Any policy that favours one thing over another isn't helpful," a Microsoft Europe spokeswoman told the Journal.

"It limits choice rather than increasing choice."

Not alone

But that argument has failed to convince a number of other countries.

Mexico, for instance, has mandated open source in its education system - although it is widely believed to have botched the implementation.

And Peru is considering a law mandating open source software.

Microsoft wrote protesting about the law and warning of collapsing software markets and portraying a nightmare scenario of incompatibility.

But the answer - from a Peruvian congressman - refuted the letter point by point.