Microsoft never liked open technologies and I am not just talking Open source here. I mean just having something that can play along with other companies' technologies. ActiveX or Frontpage extensions anyone? At this day and age though, even Microsoft has to reconsider past practices. With many users jumping train to other Operating Systems and other companies pushing web products in the market, it would stupid not to support them if you are building a web service.
Last month Microsoft introduces Office Web which is a lightweight version of Microsoft's office that runs as a web service. Microsoft now announces that the Office Web will be compatible with Linux and the iPhone. That means that users of Safari and Firefox will be able to use it as well. I am guessing here that Microsoft is becoming increasingly alarmed by Google's policy of run everything everywhere which is gaining momentum. With so many Mac OSX, Linux and iPhone user's out there Microsoft just could not afford to loose more users.