500px is an online community of photographers and photography enthusiasts who can showcase, buy, and sell art. Code examples might be useful to interact with the API capabilities before reading and writing data for new applications. Languages include PHP, Ruby, Java, Objective-C, and Python.
Instagram made API news today with new comment features, and a major upgrade. The Instagram Platform API has upgraded to Facebook's Graph API. This allows greater flexibility to access Instagram data from third party tools. Instagram commented that the API will be available to all developers soon.