You program "Apps" for it that work very much like Facebook Apps. It's all web standards: get an oath token with sufficient scope from the user and then use the

You program "Apps" for it that work very much like Facebook Apps. It's all web standards: get an oath token with sufficient scope from the user and then use the new _api to get data in and out. .net, Azure and javascript are supported and documented best, but you can use any language and run SharePoint apps on any platform.