Microsoft has unveiled a cloud computing service, in which data and applications will not be stored on individuals' computers.
The new platform, dubbed Windows Azure, was announced at Microsoft's Professional Developers Conference in Los Angeles.
The platform was described by Microsoft's chief software architect Ray Ozzie as "Windows for the cloud".
The framework will be offered alongside the next Windows release, Windows 7.
The move sees Microsoft taking on established players like Google and Amazon in the rapidly growing business of online software.
The aim is to allow developers to build new applications which will live on the internet, rather than on their own computers.
Microsoft believes consumers will also want to store far more of their data - from letters to photos to videos - on the servers in its "cloud" of giant data centres around the world, so that it can be accessed anywhere, from any device.