Google has just released a set of common APIs for building social applications across the web, called OpenSocial. These APIs are meant for developers of social applications and for websites that want to add social features.

OpenSocial will unleash more powerful and pervasive social capabilities for the web, empowering developers to build far-reaching applications that users can enjoy regardless of the websites, web applications, or social networks they use. The release of OpenSocial marks the first time that multiple social networks have been made accessible under a common API to make development and distribution easier and more efficient for developers.

The proliferation of unique APIs across dozens of social websites is forcing developers to choose which ones to write applications for – and then spend their time writing separately for each. OpenSocial gives developers of social applications a single set of APIs to learn for their applications to run on any OpenSocial-enabled website. By providing these simple, standards-based technologies, OpenSocial will speed innovation and bring more social features to more places across the web. Users win too: they get more interesting, engaging, and useful features faster.

“The web is fundamentally better when it’s social, and we’re only just starting to see what’s possible when you bring social information into different contexts on the web,” said Jeff Huber, senior vice president of engineering, Google. “There’s a lot of innovation that will be spurred simply by creating a standard way for developers to run social applications in more places. With the input and iteration of the community, we hope OpenSocial will become a standard set of technologies for making the web social.”

One of the most important benefits of OpenSocial is the vast distribution network that developers will have for their applications. The sites that have already committed to supporting OpenSocial -- Bebo, Engage.com, Friendster, hi5, Hyves, imeem, LinkedIn, mixi, MySpace, Ning, Oracle, orkut, Plaxo, Salesforce.com, Six Apart, Tianji, Viadeo, and XING -- represent an audience of about 200 million users globally. Critical for time- and resource-strapped developers is being able to “learn once, write anywhere” -- learn the OpenSocial APIs once and then build applications that work with any OpenSocial-enabled websites.

Several developers, including Flixster, FotoFlexer, iLike, RockYou, Slide, Theikos, and VirtualTourist have already built applications that use the OpenSocial APIs. A developer sandbox will be available soon at http://sandbox.orkut.com so developers can go in and start testing the OpenSocial APIs. The goal is to have developers build applications in the sandbox so they can deploy on orkut and ultimately other OpenSocial sites.

The existence of this single programming model also helps websites that are eager to satisfy their users’ interest in social features. More developers building social applications more easily translates directly into more features more quickly for websites.

The common method that OpenSocial provides for writing social applications means that websites can engage a much larger pool of third-party developers than they could otherwise. They can direct resources that might have gone to maintaining a proprietary API and supporting its developer community to other projects.

Because OpenSocial removes the hassle from developing for social networks, developers can unleash their creativity anywhere that catches their interest. This will translate into a wave of social features in contexts outside of the personal entertainment and games that are traditionally thought of as the social web.

OpenSocial resources for developers and websites will be available here.