At 3scale we're often asked, "Which Web architecture will win? HTML5 or App+API?" And our answer is generally, "Both, they are converging." A great recent post by Zendesk's Alexander Aghassipour and Shajith Chacko on Single page apps illustrates a big piece of how this is happening.
APIs (Application Programming Interfaces) are becoming a common sight as more and more companies launch them. However, they are often perceived as add-ons to existing services rather than of primary importance. However, recent rapid growth in the number of APIs and more financing in the API infrastructure space (for providers Mashery and Apigee) suggests that there may be something deeper worth looking into. In many cases, it is the APIs that are becoming the main event and not the individual apps they drive.