The Web is slowly changing from a visual resource designed to externalize information to people, to a non-visual resource that's able to facilitate machine-to-machine communications. The catalysts of this change are non-visual communications that are enabled using APIs, or Application Programming Interfaces. These APIs allow you to leverage within your own application both behavior and data that somebody else has built and hosted, as if both the functionality and information were local.

APIs are nothing new. The way we're learning to leverage them on the platform of the Web is. I've worked with Internet-delivered APIs for over 10 years now, but it's just recently that this space has become very interesting, and this is clearly the next revolution.

Where do you find these Web-delivered APIs? API directories, of course, with the best known and most popular being found at www.programmableweb.com. There you'll find thousands of APIs from hundreds of providers, offering up everything from an API to post and pull from Twitter, to more business-oriented APIs for financial services applications, or other core business needs.

Perhaps the best way to understand this is to walk through an example, such as ZoomInfo, that provides a people search API with the following capabilities.

"The ZoomInfo Public API provides free access to ZoomInfo's people database and company database that contain over 40 million people and nearly 4 million companies, respectively. The ZoomInfo people data and company data are accessed using a simple REST query API."

Thus, the API, now in beta, is provided as a service to you, over the Internet, to access the ZoomInfo people database, leveraging RESTful services.

"The ZoomInfo company search API gives you the ability to:

• Search for any company in the ZoomInfo company database by name, domain, industry, keyword, geography, or company size.
• Get detailed information such as description, industries, address, stock ticker, key people, mergers and acquisitions, and more.
• Get a list of competitors for any company in the ZoomInfo company database."

Invoking an API, locally or over the Internet as is the case with ZoomInfo, is typically straightforward. For instance, a people search for John Smith, leveraging the ZoomInfo API, may look like this.

You would then get a return XML, with the structure and the information you requested, ready for consumption into the application.

The core value of these APIs is the ability to mix and match them to solve core business problems or augment business processes, or create unique and innovative applications. For instance, how about mashing up Twitter posts around a particular stock with the trading volume for that stock over a period of time? Or, tracking the weather to determine how it affects product deliveries in a particular region? You get the idea.

Again, the use of APIs is nothing new. However, the types of APIs that are available on-demand, the ease of access, and the value that they can bring to any Internet-connected application is new. Also new is the shifting paradigm of the Web from a visually oriented concept to a Web that also supports more machine-to-machine behavior and information exchange.

Thus, going forward, what I'm going to cover in this new column is the quickly emerging space of API-oriented Web development, and the number, types, and concepts behind the APIs that are emerging on the Web today and how to leverage them. In other words, we'll discuss the process of extending your enterprise systems to the emerging Web, which thus provides much more value to your IT infrastructure. It's going to be a fun ride. Time to get on board.