Google’s highly anticipated OpenSocial app platform where developers can create applications that work on its own social networking sites like Orkut and any participating social networks is set to go live today. News of this was first reported by TechCrunch in September.

OpenSocial is a set of common APIs for building social applications on the web. These common APIs mean that developers only have to learn once in order to start building social applications for multiple websites, and any website will be able to implement OpenSocial and host social applications.

These APIs will allow developers to access core functions and information at social networks:

- Profile Information (user data)
- Friends Information (social graph)
- Activities (things that happen, News Feed type stuff)

Developers such as Flixster, iLike, RockYou and Slide will create apps which can be hosted on participating social networks such as Orkut, Salesforce, LinkedIn, Ning, Hi5, Plaxo, Friendster, Viadeo, Oracle, MySpace, Bebo, and SixApart.

OpenSocial is in direct response to Facebook which allows developers to create apps on the Facebook platform but which are not portable to other platforms. With OpenSocial, apps will work not only on Google but across other platforms.