Microsoft has dismissed the growing threat of Linux, hitting back at claims about the security and cost of the open source platform.

In an interview with vnunet.com Mark Greatorex, director of the .Net developer group at Microsoft, said Linux is more of a threat to Unix than to Windows.

"We desire to be the major platform of choice and we don't see Linux taking market share away from Microsoft - only Unix," he said.

"A lot of Solaris customers, but Unix generally, are starting to move to a Linux-based environment."

He argued that Linux is currently restricted to "high-volume, low-value" tasks on the edge of the network, such as file and print servers.

Microsoft and analyst IDC recently came under fire for a report claiming the total cost of ownership over five years to be almost a third more for Linux.

Analysts and developers argued that the research did not take into account the cost of training Microsoft engineers, or the extra security software and hardware needed for a Microsoft environment.

"Non-commercial software is absolutely not free," said Greatorex. "The cost of owning a Linux solution is greater over a period of time than owning a Microsoft solution."

And he hit back at the security claims, saying the company would not be "beaten with the security stick".

He cited an Aberdeen Group report from late last year that claimed there are more open source security alerts than Microsoft ones.

"The Linux environment is more insecure than Microsoft. This is an issue the industry needs to be aware of," he added.

But Greatorex's dismissal of Linux is in contrast to Microsoft chief executive Steve Ballmer's comments last September, which acknowledged Linux as a serious competitor.

And recent high-profile adoptions of Linux by the companies such as Unilever and Morgan Stanley point to the increasing acceptance of the platform by large corporate users.

Mark Blowers, senior research analyst at Butler Group, sided with Ballmer's view and said that Microsoft still has work to do to gain confidence in the enterprise data centre.

"Microsoft hasn't really cracked the data centre market by any means," he said.

"Linux is a threat to Microsoft. At the moment Linux is being used for the edge of the network stuff, but a lot of those are Microsoft print servers that are being replaced."

Blowers acknowledged, however, that much of it was down to perception, and that Microsoft had addressed robustness with its Windows 2000 platform and hardware deals with the likes of Hewlett Packard and Unisys.