WebAPI Intro

According to Wikipedia an application programming interface (API) is the interface that a computer system, library or application provides in order to allow requests for service to be made of it by other computer programs, and/or to allow data to be exchanged between them.

The same applies on the Internet for web sites and web services. They are functionalities made available by websites to their users or visitors in a programatically way. Developers can use these web APIs and enrich their applications with useful functions from third parties.

Web API is a new direction to follow by W3C in a new working group: Web APIs Working Group (Programming interfaces for Web Application development). They say:

The W3C Web API Working Group is chartered to develop standard APIs for client-side Web Application development. This work will include both documenting existing APIs such as XMLHttpRequest and developing new APIs in order to enable richer Web Applications.

Some of the most well-known web APIs are Google Maps or Google Search, Yahoo Maps or Yahoo Search, eBay API, Amazon API, Paypal API, Skype API, AOL API and many more. This website is dedicated to most of these services public available for free on the Internet, with samples and reviews.

Usually, these web API functions are available online for registered accounts. Developers need a free account with a private key, required for calling server functions. Then, all these APIs have their own rules and terms, you need to follow. It may be limitations for these free accounts. Also, commercial accounts may be available. Although, the number of calls are limited per day, the number is pretty high, okay for most of the websites and clients. Read carefully their terms and limitations.

Also, some of them are betas. From our experience they are working just fine, although they may have some bugs (it's software, isn't it?).

For more information on this subject, plus samples and links to these APIs see this site in more details. Thanks for you opinions and feedback, especially when correcting possible errors or sending us new links for other services.