Google Plans a PC Operating System

The software, called the Google Chrome Operating System, is initially intended for use in the tiny, low-cost portable computers known as netbooks, which have been selling quickly even as demand for other PCs has plummeted. Google said it believed the software would also be able to power full-size PCs.

The move is likely to sharpen the already intense competition between Google and Microsoft, whose Windows operating system controls the basic functions of the vast majority of personal computers.

“Speed, simplicity and security are the key aspects of Google Chrome OS,” said Sundar Pichai, vice president of product management, and Linus Upson, engineering director, in a post on a company blog. “We’re designing the OS to be fast and lightweight, to start up and get you onto the Web in a few seconds.”

Mr. Pichai and Mr. Upson said that the software would be released online later this year under an open-source license, which would allow outside programmers to modify it. Netbooks running the software will go on sale in the second half of 2010.