The increase in APIs has been steady and steep over the past few years. It took three years to get to 1,000 APIs and less than two years to reach the 2,000 mark. Now it is on its way to 4,000 after cresting the 3,000 total in less than nine months.

Executive Editor Adam DuVander posts that some trends are emerging as APIs increase in popularity:

• The Service is the API: APIs are launching from scratch without any associated service. The service is the API and the company is the API.
• Services Are More Useful: Urban Airship and SimpleGeo represent how services cater to developers to make their work easier. Urban Airship adds push notifications and in-app purchases to mobile applications. The SimpleGeo API stores location data for developers, in addition to providing business listing data.
• REST and JSON Are Rising in Popularity: SOAP APIs are relaunching as REST APIs. That in itself says quite a bit. XML is still tops in the directory as a data format but developers are swarming to JSON. DuVander says JSON makes it easier to read data into JavaScript without a complex parser. He also says many are also going JSON-only." In the last year 281 APIs were added that support JSON and don't provide XML."
• APIs Fuel Internal Usage APIs are turning services into one giant mashup. For example, Twitter's website is the most common way to use Twitter. That is followed by Twitter for mobile and Twitter for iPhone. All three are built on the same API available to developers.

  The APIs on Programmable Web show how infrastructures are affecting the way applications are deployed. An API infrastructure means developers can use lots of services to create apps. All live in the same ecosystem.

  As more APIs enter the stream, we will see more diversity in how services reach people and by extension will affect how people interact in a Web and app oriented universe.