Apple CEO Steve Jobs focused his keynote speech at the Apple Worldwide Developers Conference on Monday on the new version of Apple's OS X operating system, known as Leopard.

But the news that could affect the most computer users was his announcement that Apple will make its Safari web browser available for Windows XP and Windows Vista.

After a battle in the early days of the Internet that saw Microsoft's Internet Explorer squeeze out the likes of Netscape, IE dominated for years. Recently, an open-source option that allows people to write and use add-ons called Firefox has gained popularity, in part because it is believed by many to be more secure.

Slides that Jobs presented Monday said that IE now has about 78 percent of the market and Firefox about 15 percent. Safari is at 5 percent, but that is just on Apple machines.

Jobs called Safari "the most innovative browser in the world and the most powerful browser in the world" and said that is much faster than the competitors in displaying various kinds of information.

iPhone Update

While Apple announced last week that the iPhone will be available June 29, Jobs on Monday gave the detail that it will be available at 6 p.m. that day.

Because the phone will run OS X, it will run Safari, meaning that independent developers will be able to build applications that will run on the hotly anticipated phone, Apple's first move into mobile phones.

Jobs has promoted the device -- which features a large touch screen and no input buttons -- as a great phone, music player and mobile computer.