What Google's new hire was doing at Microsoft

It's easy to understand why Microsoft might be a tad worried by Kai-Fu Lee's decision to join search king Google.

Lee, a former corporate vice president of Microsoft's Interactive Services Division, was hired by Google to open a China research and development center, the company said on Tuesday.

The problem is, Lee had been working on speech recognition technology for Windows, and specifically, for Longhorn, the oft-delayed next version of the operating system. Microsoft on Tuesday filed a lawsuit claiming that Lee breached Microsoft's employee confidentiality and non-compete agreement.

Lee joined Microsoft in Asia back in 1998, and founded the software giant's China research lab under Rick Rashid, who heads the company's research division. In a meeting with CNET News.com editors last year, Lee said his work was centered on prototyping new user interface technology, advanced search technology, natural language interfaces and speech recognition.

At least some of that technology is destined for future versions of Windows, Lee said at the time. "We're working on Longhorn search technology, the interface and other technology," he said.

Microsoft has become increasingly concerned over Google's hiring of some of its engineers. For example, over the past year or so, Google has hired Mark Lucovsky, a Microsoft "distinguished" engineer and key Windows architect, and Joe Beda, who's worked on the software giant's next-generation graphics engine, Avalon, which will also be a key part of Longhorn. Adam Bosworth, who joined Google from BEA Systems last year, previously worked for Microsoft where he helped define the company's XML strategy, among other things.