Flickr has added more real-time goodness to their photo API. Using a publish / subscribe (PubSub) system, developers can now receive real-time updates across millions of photos across Flickr friends, Flickr Commons, and by tags and geo-location using the Flickr Real-Time API.
For a while now the Flickr API has supported personal and friend photo subscriptions like this:
Now you can also request real-time updates from over 50 institutions participating in the Flickr Commons including NASA, The Library of Congress, and the National Archives of the U.S. and U.K. by sending commons subscription requests to flickr.push.gettopics:
In addition to Flickr Commons, Geo subscriptions are available as well. Using the geo topic type you can subscribe to photos from a particular geographic area, specified as either a set of WOE IDs, Flickr Place IDs, or by a point and a radius. Radius queries are great for doing searches for photos in areas that are well known, by just creating a circle on a map, while WOE IDs are useful since they represent many well-known geographic features such as cities and airports.
Beyond friends, and geo subscriptions, Flickr has also opened up subscriptions for any tag. Developers can include any comma separated list of tag names and receive tag based photo updates:
With a photo archive the size of Flickr real-time discovery is important to empower developers to find what they are looking for, and keep their applications and site content fresh. But the move also probably reflects a technical decision to make the API more efficient, and reduce the number of calls made by apps polling the API regularly. Either way its great to see ehnancements from the popular photo sharing API, and the pioneer in the web API space.