Yahoo! has joined forces with its big rival with the decision to support Google’s OpenSocial developer platform for social networking sites.Google created the interface to allow programmers to develop social networking applications, using standardised code, that will run on more than just the one website.

Yahoo! has joined leading social networks such as MySpace, Bebo and LinkedIn to support the project, which Google has described as a non-commercial initiative that will work with external developers to enhance and improve the platform.

The most conspicuous absentee from the alliance is Facebook, which has a developer platform of its own but whose applications will only run on Facebook.

OpenSocial is part of a drive, which includes the OpenID movement, to open up the new face of the web, driven by the community, through increased standardisation and cooperation.

OpenID, a decentralised single login system, is also gathering momentum with several key players, such as AOL, already on board.

Yahoo! vice president of platforms, Wade Chambers, said that its support built on similar efforts with the OpenID community and would expand the opportunity for developers and publishers to benefit from an open and increasingly social web.