The area of API management service providers is something I've been tracking on since I started API Evangelist. I did a round-up of API service providers in 2011, and again covered the expanding world of API service providers in 2012.
As the definition of what I consider API service provider expands, I try to break off into their own projects as I've done with API Aggregation, API Reciprocity, Backend as a Service (BaaS) and Real-Time.
For now "API Management", is the catch all project category for any API related online service that I haven't broken off, and will remain the home for the classic definition of what is API service provider like 3Scale and APIphany.
I used to showcase "service providers" and "tools", but now I will bundle services and tools into these different areas. Then using my Hacker Storytelling format I will be publishing news, analysis, data as JSON and different snippets of code that let you view and interact with these API project areas.
Using this project you can browse all API management providers, with the list of providers listed by their API Stack Ranking, which is based upon internal signals from the companies themselves, external signals from developers and the tech blogosophere, as well as analyst signals based upon my curation, notes and insight.
My goal is to make all of my research as accessible as possible, allowing anyone to learn about APIs and put my research to work changing the companies where they work, and the industries they operate within.