The Facebook Real-Time Updates API allows developers to create applications that respond to real-time data updates from Facebook subscriptions. Objects that can be subscribed to are: user, permissions, page.
Sure, Facebook filed for an IPO today, but it also provided developers some great guidance on using real-time features in the Facebook API. And while Bloomberg's lead news story is the Facebook IPO, in the API world it's probably more interesting to look at Bloomberg's new open platform. Plus: why we can't agree about REST, API-related job growth and a whopping 28 new APIs.