Yahoo! Social offers a PHP SDK currently in Alpha stage. The main difference between PHP5 and PHP is the available storage. As the site states, the new implementation is more flexible because developers can store OAuth tokens in a PHP session, in a database, or in memcache. Requirements showcase OAuth, Open ID, OpenSocial, and JSON with its respective redirected links. Examples include fetching YQL, fetching social data, fetching people and activities with OpenSocial, and adding contacts. Tests offer functional examples and results as well. Despite the fact that the SDK is in a experimental stage, developers have the opportunity to plan social directory and contact applications in advance.