Microsoft Corp. is developing software for high-performance computers often used in engineering and science research, in a move that puts the company in another head-to-head battle with open-source developers.

Microsoft Chairman Bill Gates plans to announce the release of another test version of the company's software at a supercomputing industry conference Tuesday in Seattle.

Craig Mundie, one of Microsoft's chief technical officers, said the company is entering the market as high-powered computers are becoming more affordable, allowing the market to expand to a point where it makes sense for Microsoft to get into it.

Such computers are used for computing, storing and sharing data for a wide variety of uses, ranging from creating better medications to engineering automobiles.

While such computers used to easily cost as much as $1 million, Mundie said some are now available for as little as $4,000 or $5,000.

The Microsoft product, called Windows Server 2003 Compute Cluster Edition, is due out in the first few months of 2006. The company has not yet set pricing.

With its new software, the Redmond company is aiming for small-to mid-sized versions of the powerful computers, mainly the type that are used by academic researchers and businesses. Mundie said the company also is hoping that its software will make it easier for less technically savvy people to set up such systems.

Currently, most such computers are run on custom-rigged software using Unix or open-source Linux technology.

Unlike Microsoft, which believes that software blueprints should be closely guarded, people who develop using open-source technology hold that the underlying code and any developments should be freely shared.