API management is the process of creating and publishing APIs, enforcing their usage policies, controlling access, nurturing the subscriber community, and collecting and analyzing usage statistics.
While solutions vary, the following functionality is typically found in API management products:
Gartner estimated API management to be $70 million in 2013 and growing at 40% a year.
According to Forrester Research, in US alone, annual spent on API management was at $140 million in 2014 and expected to grow to $660 million by 2020. By that time, global sales are expected to exceed a billion dollars.
The wide adoption of APIs led to the emergence of off-the-shelf API management products, open-source projects, and SaaS offerings.
Forrester Research includes the following API management vendors in their reports: