"There will still be a lot of proprietary innovation in the browser itself so we may need to have a rendering service," he said.

Then came the startling revelation that Microsoft may also adopt an open source browser engine.

"Open source is interesting," he said. "Apple has embraced and we may look at that, but we will continue to build extensions for IE 8."

Ballmer also admitted Microsoft got delayed with the transition from IE 6 to IE7 during the development of Longhorn, which became Vista. "But I don't what to go there."

Developers want money