Microsoft Struggles to Maintain its Bloated Operating System

Microsoft insists each version of its Windows operating system must be backward-compatible with previous iterations, a strategy that may have been partly responsible for last weekis announcement that Windows Vista will miss its original December shipping target. Steve Lohr and John Markoff reported on that theory for The New York Times on Monday, noting that Windows 95 had 15 million lines of code while Windows XP has 35 million and Vista will have 50 million.

"Windows is now so big and onerous because of the size of its code base, the size of its ecosystem and its insistence on compatibility with the legacy hardware and software, that it just slows everything down," David B. Yoffie, a professor at the Harvard Business School, told the reporters. "Thatis why a company like Apple has such an easier time of innovation."

Mr. Lohr and Mr. Markoff also cited an internal memo written last October by Microsoft CTO Ray Ozzie, who said: "Complexity kills. It sucks the life out of developers, it makes products difficult to plan, build and test, it introduces security challenges and it causes end-user and administrator frustration."

James Allchin leads the Vista team and was the one who made the decision to push back the release; he will retire after the operating system ships. Last Thursday, Microsoft placed Steven Sinofsky in charge of product planning and engineering for Windows and the new Web service Windows Live.

"But this doesnit seem to do anything to address the core Windows problem; Windows is too big and too complex," Michael A. Cusumano, a professor at the Sloan School of Management at the Massachusetts Institute of Technology, said.

"Microsoft feels it canit get away with breaking compatibility," added Stanford University computer scientist Mendel Rosenblum. "All of their applications must continue to run, and from an architectural point of view thatis a very painful thing."

Mr. Lohr and Mr. Markoff noted that thousands of engineers work on Windows, whereas Apple has 350 programmers and less than 100 testers on Mac OS X, according to two unnamed Apple employees. Of course, Apple "does not have to work with the massive business ecosystem of Microsoft," the reporters noted.