Stone and Williams will continue to advise Twitter on strategic matters, but devote the lions' share of their time to The Obvious Corporation, Stone told the Aspen Ideas Conference at the ski resort on Tuesday.
The pair, along with others such as Jack Dorsey, who now runs payments service Square, created the four-year-old website that allows users to send 140-character messages across the Internet. It has grown into a microblogging phenomenon used by celebrities and heads of state alike, hailed at times as a crucial tool in promoting the free flow of information.
Neither Stone nor Williams told conference attendees explicitly what they intended with Obvious, apart from saying that they were excited about building projects that will improve people's lives.
"All the biggest ideas are obvious in retrospect," said Williams. "If we get as lucky as Twitter, that would be great."
Dick Costolo replaced Williams as Twiter's CEO in October, a move Silicon Valley sources have said re-focused the microblogging sensation on monetization, or translating its fast-growing pool of users into revenue.
"The Twitter crew and its leadership team have grown incredibly productive. I've decided that the most effective use of my time is to get out of the way until I'm called upon to be of some specific use," Stone said in a blog post. http://www.bizstone.com/2011/06/its-so-obvious.html
"Our plan is to develop new projects and work on solving big problems aligned along a simple mission statement: The Obvious Corporation develops systems that help people work together to improve the world."
"This is a dream come true!" Stone said.
In a conversation with Walter Isaacson, the Aspen Institute's chief executive, the duo skipped from topic to topic, flummoxing audience members hoping for clues on their new venture.
They discussed the advantages of closed versus open systems online; how the Internet was changing philanthropy through services such as Kickstarter that allow crowdsourced funding; and how the Internet has affected distribution of content much more than content itself.
"There are more fundamental things than how distribution evolves to change publishing," Williams said.
The two charmed the audience, frequently drawing laughs with their deadpan wit. Stone described himself and Williams as "hallucinogenically optimistic", while their Obvious partner Jason Goldman, formerly vice president for product at Twitter, "is always like, 'here are the 10 ways we can get screwed'."
Social networking services like Twitter and Facebook are increasingly challenging established online powers like Google Inc and Yahoo for Web surfers' time and advertisers' dollars.
Twitter, which began courting advertisers one year ago, is still in the early stages of building a business. The company is expected to bring in about $150 million in ad revenue this year, compared with Facebook's roughly $4 billion in ad revenue, according to research firm eMarketer.
In December, Twitter was valued at $3.7 billion in a $200 million funding round led by venture capital firm Kleiner Perkins Caufield & Byers. An auction of Twitter shares on the secondary market in March suggested investors were valuing the company at more than $7 billion.
One audience member asked if there was a bubble in technology.
"Maybe investor excitement is outpacing the development," Williams allowed. But he was firm about his corporate progeny.
"I'm holding my Twitter stock long-term," he said. "If there is a correction, these things always go in cycles. So that will be fine."