Use this PHP library to interface with the App.net's Stream social networking API. Access application functions like: social graph, messaging, and places. Documentation, including code examples and access to other libraries is available on the library's GitHub page. Note that the API is in development and the library continues to be updated. The developers note that some updates may break backward compatibility for older versions.
Every day Foursquare users create millions of check-ins using the location-sharing platform. Those may be only a small fraction of the traffic seen by its API, which we've estimated receives at least 5 billion requests per month. The company continues to expand the local data made available via its API, so developers of all sorts are finding it a rich resource for building their apps.
Do you remember a time when keeping track of your social networks meant only checking your inbox? Neither do I, but Microsoft is working on a solution that will eventually allow Outlook to integrate with a number of social networks like LinkedIn, Facebook and MySpace with the Outlook Social Connector.
PubSubHubbub. Say that three times fast. If you're not familiar with PubSubHubbub, it's an extension of the RSS and Atom protocol that allows the feed to push content out when it's updated. That's just the sort of technology we should see from check-in APIs like Foursquare and Gowalla.