We have seen an explosion in the number of APIs that are now available to developers. It seems like almost everyone has one and those that don't are scrambling to get one. The focus now is clearly not on just having an API, but having a "great API." Two excellent presentations from Cloudstock, held earlier this month, give you an overview on the current state of the API market and tips on what makes a great API.
Programmable Web Founder John Musser gave a presentation titled Open APIs : State of the Market, which we also referenced in Open APIs: Why Bother? The presentation draws heavily on data from the ProgrammableWeb directory, including the numbers behind the rise of JSON over XML and REST over SOAP.
Evan Cooke of Twilio (a ProgrammableWeb sponsor) made an excellent presentation titled Building a Great API. The presentation touches upon how to build a good API by giving examples of a bad API design. It then goes on to discuss the Design principles of Good API Design, Examples of Well Designed APIs and What constitutes a Good API. It is worth reading and keeping these points as a check list, whether you already have an API or are planning on an API. Or maybe use the checklist as you are evaluating APIs to use.
On a side note, in a news item that should be of interest to developers, eConsultancy has listed a set of 5 APIs that they believe developers should know about. The reasoning behind the selection of these APIs is that instead of building applications on a platform, these APIs allow one to pretty much build whatever application they want. The APIs are : Online Video Encoding Service API Zencoder, telephony API Twilio, automated Text Analysis API Saplo, Paypal Adaptive Payments and the location services platform SimpleGeo API.
There has never been a better time to be a developer, especially with the riches available in the form of various APIs, which allow you to pretty much build the application that you have in mind. If you're looking to launch an API of your own, the above presentations and examples are worth keeping in mind as you plan your way forward.