Analysts noted that Google soon will face more competition from Microsoft Corp., which is developing a competing product.

In their letter, Google's founders made it clear that they want the company to retain its mystique and its creative, entrepreneurial spirit. For example, they declare they do not intend to be driven by pressure to boost quarterly profits or to provide Wall Street analysts with guidance about the company's outlook for earnings, as most public companies do.

"They have pulled back the curtain as much as they need to and no farther," said Jupitermedia Corp. analyst Nate Elliot. "They will refuse to give guidance, and not comment on their own strengths and weaknesses, or strategies or plans."

Google's ambitions to avoid quarterly earnings pressures will be aided by having two classes of common stock, with the founders controlling super-voting shares that will keep them in charge of major decisions and avoid unwanted interference by outside shareholders. It will also, among other things, make a corporate takeover without their consent virtually impossible.

"In the transition to public ownership, we have set up a corporate structure that will make it harder for outside parties to take over or influence Google," they wrote. "While this structure is unusual for technology companies, it is common in the media business and has had a profound importance there. The New York Times Company, the Washington Post Company and Dow Jones, the publisher of The Wall Street Journal, all have similar dual class ownership structures."

But analysts and tech executives said Google is likely to find that the harsh realities of life in the public spotlight will put the company on a different course. Jim Davis, senior vice president of privately held software giant SAS, said Google won't be able to avoid bowing to pressure from Wall Street for short-term earnings growth.

"Their focus will change, particularly in upper management, from what they have been doing in the Google labs perspective, to what they have to do to manage their finances on a quarterly basis," Davis said.

The Google brand has spread globally despite little in the way of advertising or marketing expenditures, and its site is so popular that it's name has become a verb. Google's use of an electronic auction to sell stock in the initial public offering reflects its iconoclastic culture.

"This is groundbreaking," said Standard & Poor's analyst Scott Kessler. "They are trailblazing in doing it. They like that."