Microsoft has accused Linux of having "support issues" as the Redmond giant unveiled the first beta of its Windows Server 2003 Compute Cluster Solution operating system for high-performance computing (HPC).

The new software clusters four, eight, 32 and 64 machines, and has the ability to run jobs across different machines with different requirements and memory demands.

Microsoft is looking for increased leverage in its bid to gain a foothold in HPC installations, most of which are dominated by Linux.

Bob Muglia, senior vice president of Microsoft's Windows Server division, told delegates at the company's Professional Developer Conference: "[Open source] applications are not integrated into companies' Linux environments. They are built on one-off environments so there's no consistency. There are real support issues."

James Governor, founder of analyst firm Red Monk, said: " Microsoft's position has been almost non-existent. NT was not something that you would use in an HPC environment.

"But HPC is important because it drives some bragging and drives some customer buying behaviour further down the chain. Server 2003 Compute Cluster is about five years late but it was still critical for Microsoft to do this."

In its bid to unseat the hugely successful Apache server software, Microsoft has distributed its first developer release of the next version of IIS.

IIS 7.0, part of Longhorn Server due in 2007, copies the modular approach favoured by Apache. This will make it easier to add or remove services, and launch the web server without rebooting.