Microsoft is unveiling a new operating system on Tuesday, but don't get too excited.

Think of Singularity as "a concept-car OS," said Rick Rashid, general director of Microsoft Research. Microsoft is making the prototype OS available free to the academic and research communities in the hope that they'll use it to develop new kinds of computer architectures.

It's difficult for the academic community to experiment with computer architectures, he said. Singularity is designed to make it easier for researchers to test how operating systems and applications interact with each other, he said.

"It's a new system built from the ground up, with the specific goal of being more reliable," Rashid said. Microsoft hopes that Singularity will help improve software reliability and boost research in programming languages and tools.

Singularity is available on Microsoft's CodePlex Web site. It was unveiled on Tuesday at TechFest, Microsoft's annual showcase of projects from its research division.

Rashid also showed off BEE3, a hardware project that Microsoft designed with researchers at the University of California, Berkeley to let researchers experiment with computer architectures. "The idea behind it is to build a computer system that is configurable," Rashid said. "You can program this computer to be another computer or do another kind of architecture or experiment with new kinds of algorithms," he said.

Rashid and his colleagues are demonstrating technologies that Microsoft's research group is working on. Some of the projects ultimately contribute to Microsoft products but others, like vaccine design and quantum computing, often seem irrelevant to the software giant's core business.

Still, Rashid said that the best return on any investment that Microsoft makes consistently comes from its investment in Microsoft Research. The group generates about a quarter of the company's patents, he said.