The Two Kinds of Interfaces in Web 2.0

In general, there are two kinds of interfaces in Web 2.0

• API (Application Programming Interface)
  This is the “web as platform” interface. Companies with data stores (eBay, Amazøn, Google) create APIs for developers to hook into. In doing so they provide public access to information that would have been private previously, completely changing the way that people interact with the site. The Google and Yahoo Maps APIs are two of the latest to be released. These are the building blocks of web services.
• AII (Application Interaction Interface)
  This is the interaction interface that is built on top of the APIs, and is most often called a web application. Developers build Web 2.0 interaction interfaces to provide value above and beyond what the solitary sites can add themselves.

Andale.com is a great example of an interface built on top of an API, the eBay API. On Andale you can track the selling activities of products previously sold on eBay. This allows a much clearer picture of what items actually sold for, and it is functionality that eBay doesn’t provide itself.

Interestingly, most Web 2.0 companies start out with both interfaces. Amazon, for example, had the Interaction Interface years before the Programming Interface. I wonder if there are any companies out there building just the API, without providing an Interaction interface. We’ve got lots of sites with just the Interaction Interface, but few with only the Programming Interface. (Andale is just the Interaction Interface, of course…but I could imagine them adding even more value with their own API.). Also, it could be argued that an RSS feed is an simple API, of sorts.

Over time, companies with valuable content might just have APIs to that content, without providing their own interface. After all, interfaces are hard, why not let other people create them? You’ll still be able to license that content assuming it is providing value.

Know of any API-only sites? | Bokardo Interface (AII)