Enterprises rarely move as quickly as the rest of the web. Many, including us at ProgrammableWeb, have been saying for some time that big companies will embrace the open API movement. It appears this may be happening in earnest now, as our directory hits the milestone of 8,000 APIs. And it makes sense, because APIs are helping companies do business, with the tradeoff between adding an external dependency being out-shined by the ability to move faster building upon someone else's expertise.

The Last 1,000 APIs

It's been just just three months since the directory hit 7,000 APIs, meaning it continues to grow at an incredible pace. Here are the top ten categories of the last 1,000 APIs:

Yes, the enterprise has arrived. It made the top list of the last 1,000, as well, but it's moved up. And it's joined by some similarly enterprise-y categories of financial and payment APIs. Science and government also make the list, despite being similar categories where you might not expect fast-movers.

Why Are Enterprises Embracing APIs?

It was over two years ago when we asked what happened to enterprise mashups? Once a hot topic, it seemed difficult to believe enterprises would retreat internally at a time when the rest of the web was opening up. Despite the growth of software-as-a-service and cloud-based apps, the enterprise demandes on-premise solutions. Along with API management companies now bringing their software behind enterprise firewalls, open source options have emerged.

In September Alcatel-Lucent (ProgrammableWeb's parent company) launched its open source API management software, called apiGrove. WSO2 looked to go cradle to grave with its solution, allowing companies to govern the complete API management lifecycle. Another thing open source allows is for a group within an enterprise to get started without having to go up the chain for approval. A team can toe-dip, dabbling in APIs before committing to support them.

While enterprises are certainly providing APIs at a greater rate than we saw previously, they are also likely consuming them more. Much of the growth in the enterprise category comes from services oriented toward enterprises. For example, the HireRight API is built for human resources. The HelloSign API is one of 15 e-signature APIs.

For more on what's inside this category, see our overview of enterprise APIs from September.

Governments: from Big Data to APIs

2009 and 2010 was about opening up government data, with terabytes of files made available from governments across the world. More recently we've seen efforts to make that data available as an API. The trend began in 2011, when government APIs were in the top five categories. It's become even easier with Socrata's latest platform, which turns any spreadsheet into an API. (Datownia has a similar service, but is aimed at small and medium-sized businesses).

Open data often requires huge downloads and file processing. An API gives developers access to the slice of the data that's interesting to them. For example, the US Energy Information Administration API lets developers access data by category. The Illinois Voter Registration System API has options to drill down by voting precinct.

The US Presidential election may have further ramped up government APIs, with a lot more interest in polling and campaign finance. 7-Eleven launched its first API in August for its coffee cup election predictor. Perhaps a little more scientific API came from the Huffington Post Pollster API launch.

For more on this category, see our overview of government APIs from September.

And for further analysis of API milestones, see our coverage of 7,000, 6,000, 5,000, 4,000, 3,000 and 1,000 APIs.