Whimsy is not a word often associated with a $6.3 billion company. But from doodles on its home page to puzzles in public announcements, the founders of Google Inc. inject humor into the business of running the world's fastest-growing company ever.

Larry Page and Sergey Brin, both 32, seem to work hard at being different, from their corporate motto--"Don't be evil" --to an unorthodox corporate structure and an unprecedented commitment to philanthropy. "Google is not a conventional company," Page said in a letter to shareholders. "We do not intend to become one."

Page and Brin's freedom to experiment comes from Page's brilliant approach to searching the World Wide Web, a strategy he developed while a graduate student in computer science at Stanford University. The son of a college professor, Page equated links between Web pages to citations in academic papers, which are considered more valuable if cited by other academic papers. Translating that concept to the Web meant looking at which pages linked to which, and counting and ranking Web links called for the talents of Brin, a math prodigy and another Stanford grad student.

From the start, their approach drew better results than established search engines, and the two students sensed something big.

And from the beginning, they thought big. They could organize not only the Web, itself a massive undertaking, but all the world's information. And they could make it available to everyone. Brin and Page even eyed the thousands of books collecting dust at major libraries. While still at Stanford, "we thought we should actually digitize the libraries," Page said recently.

Good works. In opening up information, they also saw a chance to make the world a better place. They wanted a company that wouldn't conflict with that principle, so they retained tight control. Brin and Page persuaded two venture capital firms to contribute at the same time, a savvy move that prevented either investor from asserting control. "It was classic divide and conquer," says David Vise, coauthor of the upcoming book The Google Story.

Brin and Page hired an industry veteran, former Novell CEO Eric Schmidt, as Google's chairman and CEO. But the founders still approve major decisions. When they disagree, they hash it out in private and present a united face.

The founders keep a tight hand on projects, personally tracking and approving products such as Gmail, Google's webmail service. They've fashioned an unusually flat structure; its few levels of management are more like a graduate school than a large company. The downside, employees have complained, is bottlenecks and the appearance of an autocratic management, says John Battelle, author of a new book about Google's business and cultural effects.

Some outsiders also complain that Google's self-proclaimed ethical superiority is wearing thin as it fiercely competes for new business and grows ever richer. The company employs more than 4,000 people, and it's sitting on about $7 billion in cash.

It seems suspect that their quirky motto can withstand the pressures of world commerce. But the founders have backed their claim to the moral high ground with a commitment of 1 percent of Google's equity and profits to good deeds. This month they announced that would amount to about $1 billion over 20 years. Characteristically, Brin and Page identified challenges unusually broad for a company to tackle, such as world poverty and the environment. And before the announcement, Brin made clear their aid goals were to be no less ambitious than in their business: "We want to be bold--we want to make a big difference."

BRIN (left) BORN: Aug. 21, 1973 EDUCATION: B.A., University of Maryland; M.A., Stanford University FAMILY: Single JOURNEY: He immigrated with his family to Maryland from Russia at the age of 6.

PAGE BORN: March 26, 1973 Education: B.A., University of Michigan; M.A., Stanford University FAMILY: Single FASCINATION: Inventors whose revolutionary contributions are unheralded