Google has released the first public APIs for Google+ so that external developers can start working with the social networking site and planning applications for it.
This first batch of APIs lets developers fetch only public data from user profiles in a read-only manner, and application calls are limited to what Google calls a "courtesy usage quota" for now.
Google sees this initial API release as the first step in building a more powerful and sophisticated developer platform. "For all of you developers who have been asking for a Google+ API, this is the start. Experiment with it. Build apps on it. Give us your feedback and ideas," wrote Chris Chabot, from the Google+ Developer Relations team, in a blog post.
Creating a thriving developer community, as Twitter and Facebook have done, has proven a must for social networking sites to succeed, so a lot is riding on the Google+ application development platform. Twitter announced in July that some 750,000 developers have built about 1 million applications for its microblogging service.
Interestingly, Google is holding off on adopting for Google+ the OpenSocial APIs that it originally developed in 2007 and championed for years as a better alternative to proprietary tools for specific platforms like Facebook's.
Google conceived OpenSocial as a standard, common set of APIs for social networking sites to adopt, so that developers could build applications once and have them work on multiple sites with little or no modifications.
The OpenSocial technology has been adopted by a number of consumer and enterprise social networking providers and its development is managed and overseen by the nonprofit OpenSocial Foundation.
When asked about plans to let developers build Google+ applications using the OpenSocial APIs, a Google spokeswoman said via email that at this time the Google+ platform doesn't support the OpenSocial APIs.
"However, we are using lots of the technology that was developed as part of OpenSocial, including the gadget application packaging model, and the Portable Contacts JSON schema, to power Google+ games. As we define the +Platform APIs, we are paying close attention to the future direction of the OpenSocial APIs, and converging wherever possible," she said.
Developers can use the OpenSocial APIs to build applications for other Google sites and services, including the Orkut social networking site and the iGoogle personalized home page service.
Google+ was launched in June in trial mode and remains available by invitation only from Google and existing members. It's estimated that about 25 million people have Google+ accounts.