“We want to take all your content on the Web and move it to a more visually immersive, immediate experience,” said Keith McCurdy, chief executive at Vivaty and a former vice president at the big game maker Electronic Arts.

Similar online services like Second Life and games like World of Warcraft have existed for years. But they are not accessible through a Web browser. Instead they require users to install large and cumbersome programs and have plenty of Internet bandwidth for a satisfyingly immediate experience.

Vivaty chat rooms, on the other hand, will be scattered across the Web. A user can stick an existing Vivaty virtual environment, or create a unique one, wherever HTML code can be imbedded. The company plans to make money partly by allowing companies to start their own virtual rooms on their own Web sites, where they can control the décor and their marketing messages.

“A lot of basic human communication needs have been lost in this age of siloed, one-to-one communications,” said Roelof Botha, a partner at the venture capital firm Sequoia Capital. “At the end of the day, we are a social species.”

Botha, one of the original backers of YouTube, is behind live Web companies like TokBox, a year-old start-up that lets people conduct face-to-face video chats on the Web, and Meebo, a two-year-old Web messaging company that introduced a new generation of networked chat rooms to the Web last year.

Chat rooms were an integral part of the online experience for users of early services like CompuServe and America Online. Characterized by names like “Single and Looking,” they often devolved into noisy chaos. Last year, Meebo’s chief executive, Seth Sternberg — who as a teenager was a chat-room moderator for America Online — introduced Meebo Rooms, a kind of 2-D version of Vivaty’s cartoonscape.