Our API directory has hit another major milestone. We now list 5,000 APIs, just a short four months since passing 4,000. No longer is the web simply about links connecting one site to another. Instead, developers are using tools to connect data and functionality from one site to another site. It's an incredible transformation that has happened over a very short period of time. APIs are at the heart of Google's strategy and they led directly to the growth enjoyed by Twitter and Facebook.
While the above graph begins with our directory in 2005, the first web API came in 2000 with the launch of the eBay API. It helps sellers list and re-list items, in addition to a number of other features that users usually perform manually at eBay's site. With an API, other companies can build tools to help automate or improve a site's own features. Several companies have built their entire product lines on top of the auction giant's APIs, including one eBay tool provider with an API of its own.
Google, Twitter and Facebook Lead the Way
Google is already a major player on the web, so it's no surprise that it is also big in the API world. Its Google Maps API helped start an API mashup movement and it's continued to add new services. We currently list 96 Google APIs, including the Google Plus API. The search giant's new social network will lean on that API to see the distribution across the web that needs to happen in order for it to be successful.
Twitter's growth can be attributed to the Twitter API, which allowed the company to be on every mobile Platform before it had an internal team building mobile apps. External developers combined their programming skills with Twitter's API to create these new ways for users to access Twitter. The official iPhone application started as a solo developer's project.
Even Twitter's search engine was built on Twitter's API. Originally called Summize, it was Twitter's first acquisition way back in 2008. The product, which was better than anything built internally at Twitter, is also available via the Twitter Search API. It's actually become quite common for an API to be built upon Twitter's APIs, which at first seems like a self-referential phenomenon. The truth is actually more altruistic: because Twitter is providing value created within its platform, those who create additional valuable insights from Twitter aim to also make it available to others for the trend to continue. Two prime examples are the influencer-spotting Klout API and real-time searching Topsy API.
Facebook was a much smaller site when it first released the Facebook Platform in 2007. The service let developers include their applications within Facebook itself and offered details about an authenticated users' friends. It's the foundation which spring-boarded social games company Zynga, which raised $1 billion in a recent IPO.
In 2010, Facebook made an even bigger API move, launching its Facebook Graph API to supply applications with all of the data within Facebook, as long as users have provided permission to a particular application. Now, rather than the web coming to Facebook, Facebook is going to the web. It's a fundamental shift where our friendships, likes and actions on Facebook can influence what we see on other sites.
Every Company Will Have APIs
Think back to the web of 1995. There were plenty of companies without websites. Very quickly, all these companies realized they needed to have a website to compete. We have seen the same thing with social media and that is the way APIs are headed. A number of big companies added APIs in 2011, including all three major U.S. credit card companies.
For a handful of forward-thinking companies, one API is hardly enough. Below is a sampling of the companies we've tracked and the number of APIs each provides.
Trends from the Last 1,000 APIs: Government, Internet, Social
The most popular API category from the last 1,000 APIs is government. In total, we list 231 government APIs and nearly half of them have been added in the last four months. Many looked to 2009 and 2010 as the years of government's embracing transparency. That was true in terms of opening up many gigabytes of data. However, it appears 2011 and 2012 are the years where that data becomes easily consumable in bite-size chunks, something that APIs make much easier than Excel files.
Some governments have lead the way. New York City's annual Big Apps contest added an API in 2011. The NYC Open Data API gives programmatic access to over 750 public datasets. We've also seen a lot of growth from governments around the world, thanks to Socrata and CKAN, platforms that make it easy to expose data.
Some government APIs are getting very specific. For example, the San Francisco Ethics Commission Lobbyist API is part of a law requiring transparency of lobbyist disclosure statements. We called it the first ethics API.
In addition to the surge of government APIs, we also saw continued interest in some of the usual categories. We now list 500 Internet APIs, which includes many cloud and platform-as-a-service APIs. For example, there are 7 Amazon Internet APIs, including the popular Amazon EC2, which probably runs many APIs itself.
API Territory: Still the Wild West
It's important to remember that this API thing is still quite new. The leaders aren't working from well-worn maps. They're creating their own paths. Like the Wild West, there's an "anything goes" approach that is bound to come under scrutiny as APIs go mainstream. Many, some even advanced developer-types, will likely call for more standardization. The chaos of an ever-expanding API universe will lead some to search for order. And a bit of order is probably needed.
But it's a lack of order that has been one of the drivers of API growth. REST is a method for accessing APIs, often over HTTP, so many APIs can be explored in a web browser, similar to visiting websites. Though few can agree on what makes something "true REST" (a 2000 paper by Roy Fielding does spell out the criteria), the simplification inherent in REST has helped make it easier for providers to implement APIs and easier for developers to consume them.
By contrast, SOAP APIs are far more ordered: methods are spelled out and made available in a machine-documented manner. Yet, with this order comes overhead. SOAP is still popular in enterprises, where company have tools that make creating and consuming the APIs easy. However, we have seen the number of SOAP APIs shrink year after year. Developers gravitate to the lower barrier of a REST API.
Where Do We Go From Here?
All signs point to hitting a couple more 1,000 API milestones this year. If every company is going to have APIs, there are still a whole bunch more on the way. Google, Twitter and Facebook are helping lead the way to an API-filled future. Amazon, eBay and Best Buy are showing us how to make money with APIs. Further, once commerce APIs get more traction, expect an onslaught of APIs that allow purchases to happen right within the APIs.