Google has released a set of open application programming interfaces (APIs) that lets developers simultaneously craft applications for multiple social networks.

The OpenSocial APIs will work with any participating social network, and allow applications to integrate information from the user's profile, along with data about friends, contacts and activities.

A programmer could use the information to build a messaging application to exchange instant messages with friends in their network, and potentially across networks.

An application developed for Facebook is limited to this one service, but a set of common, broadly supported APIs would allow developers to distribute applications across multiple social services.

Facebook was the first major social network to open up its platform to developers, and has attracted more than 5,000 applications since June.

Google, however, is going beyond building an open alternative to Facebook's APIs. OpenSocial also boasts support from enterprise players Salesforce.com and Oracle.

Early OpenSocial supporters include LinkedIn, Friendster and Plaxo, as well as the Google-owned Orkut social network. Big networks such as MySpace and Facebook are missing from the list of partners.

Google has an advertising partnership with MySpace. Facebook signed a similar deal last week with Microsoft, which is believed to have outbid Google for the agreement.