A site that can host OpenSocial applications is called an OpenSocial container. A social application is simply an application running on an OpenSocial container. Webjam is now an OpenSocial container which is able to host your OpenSocial applications.

To add an application to a webjam page, simply drag the OpenSocial Container module onto a page and enter the URL of your app. The OpenSocial Container module can be found in the Webjam toolbox.

To write an OpenSocial application, you need a working knowledge of JavaScript. Because OpenSocial applications are built as gadgets, you'll need to know how a gadget is structured, and to make your application social, you'll need to learn about the OpenSocial JavaScript API. (If you prefer, you can write OpenSocial applications using a RESTful or RPC API.)

The OpenSocial API focuses on people. OpenSocial gadgets help users share their activities with each other and access information about their friends. There are three main feature areas in the OpenSocial API:

• People and relationships. Members of social networks have friends. OpenSocial applications use the connections between people and their friends.
• Persistence. OpenSocial applications can take advantage of persistence, the ability to store data that can be retrieved when the application runs again at a later time.
• Activities. People use social applications to inform others about what they're doing: going to a movie, posting photos, and so on.

Many OpenSocial API calls are asynchronous: that is, the call returns immediately, but the action requested by the call does not take place right away. Instead, the call creates a server request to retrieve or update information. When you make an asynchronous call, you pass in a callback function. When the data is returned from the server, OpenSocial calls your callback function.

For more information about the concepts described in this section, see the following documents:

• OpenSocial JavaScript API Reference
• Gadgets API Developer Guide
• Gadgets API Reference