The Web, which began life as an open community where information and tools were freely shared across geographic, political, and social boundaries, is in danger of becoming segmented into a federation of closed camps led by a handful of increasingly powerful vendors, said Internet pundit Tim O'Reilly.

"We're heading back into an ugly time," said O'Reilly, during a keynote address Tuesday at the Web 2.0 Expo in New York City.

O'Reilly said efforts by Google, Microsoft, Amazon, Apple, and other tech vendors—as well as publishers like Rupert Murdoch's Dow Jones—to create closed communities around their products and services are jeopardizing the freedom, and the spirit, of the Web.

"It's no longer about the Internet as a platform," said O'Reilly. "It's Google as a platform, it's Amazon as a platform, it's Microsoft as a platform," he said before a packed room at the Jacob Javits Convention Center.

O'Reilly pointed to Murdoch's intention to create pay walls around Dow Jones newspaper sites, to Apple's mandatory vetting of all third-party iPhone applications, and to a recent Google announcement in which the search giant said it would release a free turn-by-turn navigation system—but only for use on phones powered by its Android operating system.

"That's not the way the Web works," said O'Reilly, founder of O'Reilly Media and the first to coin the term Web 2.0, a concept where the Web is, in effect, the operating system for the Internet. And that OS, O'Reilly said, should be made up of "small pieces, loosely joined."

Instead, vendors are attempting to create "one ring to rule them all," said O'Reilly, referring to the one ring that would supposedly give the wearer ultimate power in Lord Of The Rings.

To counter the trend, O'Reilly said vendors like Google and others "must be rigorous in thinking through the benefit to the user" when it comes to developing new products, instead of focusing on how the product will enhance their competitive position.

"Do what you do best, link to the rest," said O'Reilly, citing an oft-quoted Web 2.0 maxim.

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