Online video is hot and so are online video APIs. We recently added the Vimeo API to our listings and this brings the total number of APIs at ProgrammableWeb to 19 (see them all here). The king of these is still the YouTube API but for developers there are lots of choices.
No one needs an introduction to YouTube, which is by far the largest social video site. The YouTube API was first released in 2005, which seems like a long time back in the API timeline. At the recently concluded Google I/O 2012, YouTube officially announced a series of new APIs and enhancements that focused on mobile video, user engagement and Analytics.
With the real-time web being claimed by some to be one of the core components of Web 3.0 it's unsurprising that we are seeing more real-time APIs and real-time mashups being developed. One mashup has just been created using Kwwika and Superfeedr to demonstrate how two real-time platforms can be integrated to create a real-time news reader application.