Measuring the Popularity of APIs

How do you measure the popularity of your API, or someone else's API?

If its your API, hopefully you have metrics established for every part of your API and supporting API area.

But how can we measure the API space as a whole? I get asked a lot about, what are the top APIs out there.

ProgrammableWeb measures popularity by the number of mashups that are built on an API. Using this metric, Google Maps, Twitter, Flickr and Youtube rise to the top.

Not all APIs are suited for mashups, and we definitely need more ideas of how to measure popularity and usage of Open APIs.

I would start by using Alexa, Compete, and Quantcast who provide SEO related analytics and ranking for web sites.

Next I would look at the number of partners an API has showcased in their developers area or web site.

After partners I would look for the number of developers showcased as part of an API ecosystem. Not all APIs provide tools for developers to have a public profile, but if they do, this can be an important measurement.

After the number of partner and public users, I would take a close look at how many applications are developed on a platform. Both internally and community developed applications. These represent completed projects where developers have successfully integrated with an API.

Then I think overall API community activity and resources would be a good thing to measure. How many code samples, language kits, FAQ, forum posts, and other resources are provided. This reflects the amount of resources a company and community has put into an API.

There is no perfect way to measure the success and popularity of an API on the open Internet, but these are a few ideas for variables the industry might consider when developing an algorithm for tracking the popularity of APIs in this fast growing space.