The sheer number of worms and viruses directed at Microsoft's Windows operating system and Internet Explorer browser have many in the computer industry wondering whether we would all be more secure if more users relied on alternatives to Microsoft's products.

That description appeared to fit about two thirds of the few hundred system administrators and engineers attending a debate between two prominent security experts at the Usenix 2004 conference in Boston on Wednesday. A show of hands before and after the debate confirmed that most users in attendance would prefer a more diverse group of operating system and Web browser software.

A monoculture, whether it be in biological terms or in computing terms, has been shown to be inherently dangerous to members of that group, said Dan Geer, currently the chief scientist at Verdasys. Geer was formerly chief technical officer at security company @stake until he was fired last year for authoring a report critical of Microsoft's dominance of the computing industry and the insecurity of its products that stems from that position. Microsoft is an @stake client.

Operating system diversity can be a relevant part of a secure network, but forcing companies to diversify their operating systems is a tough proposition in a time of declining IT budgets and heavy emphasis on return on investment, said Scott Charney, chief trustworthy computing strategist at Microsoft.

Geer likened the evolution of the computing world to the evolution of life on earth, putting the computer industry at around "the blue-green algae" stage of development. Early organisms were forced to evolve and diversify to deal with threats, and the computer industry must also diversify if it is to confront the serious threat presented by professional hackers, he said.

"Nature has shown us that a monoculture is a primitive state, or a dying gasp," he said.

Not every monoculture leads to strife, Charney countered. He pointed to Southwest Airlines, which only uses Boeing 737 airplanes in its fleet. This allows Southwest to take any one of its pilots or maintenance staff and put them to work on any plane in its arsenal, which saves training costs, he said.

The airline's reliance on the 737 is a bit of a gamble, since any directive from the U.S. Federal Aviation Administration grounding the 737 would effectively ground all of Southwest Airlines, Charney said. But this is a tradeoff that Southwest views as acceptable given the cost savings it realizes from the decision to standardize on the Boeing 737.

Likewise, enterprises that standardize on Microsoft products are taking a risk that if Microsoft's products are vulnerable to attacks they could lose important data, Charney said. However, if those enterprises use products from a single vendor it makes it easier for their IT staff to roll out patches and critical updates, and saves the training and education costs required to teach those employees how to run other operating systems, he said.

The problem with that argument is that there will always be a few companies or individuals that fail to patch their systems against new threats, and those infected systems can be used to create havoc across the entire Internet, Geer said. If that's going to happen anyway, the companies that have chosen to rely on a different operating system or Web browser will be protected against attacks launched at the vulnerable products, he said.

"I don't care what you get. I just don't want it," Geer said.

Ultimately, software vendors must stand up and take accountability for their products, Charney said. In the past, customers haven't been as concerned about security and didn't demand that vendors product secure products, but that has changed drastically over the past few years, he said.

Geer called the vulnerabilities in Microsoft's products "a national-security issue," claiming the issue is far too important to the health of the Internet to leave up to the software vendors themselves.