Although Microsoft has not disclosed any plans to bring its Office software to the iPhone as a native app, the company is working on a suite of Office Web applications that will support both desktop and mobile browsers, according to Ars Technica. The web-based tools will include Word, PowerPoint, Excel and OneNote.

Office Web will a different set of utilities than the Office Mobile package. The company recently announced a new partnership with Nokia to bring Office Mobile to the Symbian platform. Nokia executive Robert Anderson claimed the alliance will give RIM a "run for their money," although the companies downplayed suggestions that Apple was the target.

The desktop version of Office Web will initially support Internet Explorer 7/8, Safari 4 on Mac, and Firefox 3.5 on Windows, Mac and Linix. The free version will serve ads through Windows Live, or customers can purchase subscriptions. The ad-free variant will also be free for all Office volume-licensing customers.

The Office Web apps for mobile browsers are still in the early phases of development. The apps for desktop browsers are expected to be ready sometime in the first half of 2010.