The 500px Ruby wrapper by Chris Micacchi has been designed to interact easily with the API capabilities of search, retrieve, and upload photos. It aims to reuse HTTP connections. 500px is a community of photographers who can showcase their projects, discover new photography styles, and find royalty-free art.
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.
Late last year, Google announced a limited preview of its Cloud Vision API beta. After massive participation in the preview, Google has opened its image analysis API beta to the broader developer community. Apps submit images to the platform where a wide array of image attributes are detected.