Google built a feed platform that is freely available for any user with a Google account. The first implementation of the Google feed platform is the Google Reader lens, already used by thousands of Google users. The Google feed platform is web-based and therefore works with any operating system. It can be used as a pass-through for one feed at a time for small implementations or a full aggregator backend. It’s running on the Google’s expansive (and expensive) back-end hardware and network, creating fast response times and high reliability.
Atom 1.0 output
Enclosures are passed-through directly into the final markup. Any enclosure presented by Google Reader may or may not exist and has not undergone any pre-processing by Google.
Read and unread status is one of many different pieces of metadata surrounding every exposed item.
The Google Reader platform display’s a user’s current, past, and inactive subscriptions. You may view details such as when the user subscribed to the feed and when it was last recognized as modified.
Each user can apply his or her own tags to any feed. A feed about gadgets may be tagged “computers,” “electronics,” “gadgets,” and “toys” for example. Tags allow loose organization of feed data and all Google Reader data is retrievable at the tag-level.
Google applies relevance to any group of items you would like to retrieve. Relevance is Google’s own black box magic that takes into account link activity, word count, and other metrics to help users focus their attention on a smaller subset of items.
The Google Reader platform allows the synchronization of all of your feed aggregator information across machines and applications. You can synchronize data such as tags, read status, and even flag status. Developers may authenticate users using stored cookie data, name and password directly in the URL, or via SASL.
The Google Reader platform is still in final development and therefore not an officially announced Google developer option. You can track the latest news on the Google Reader blog and read my unofficial Google Reader API documentation for development details.