Google Contacts API gives client applications access to a user’s contacts list where the application can create new contacts, update or delete existing ones, or query for contacts that match particular criteria. This tutorial explains how to implement the API in C# and ASP.NET with OAuth 2.0.
We write a lot about the growth in the number of APIs on ProgrammableWeb. But how about usage? Some APIs see so many requests that they measure in billions. We refer to these companies as the API Billionaires Club. The image below, which comes from ProgrammableWeb Founder John Musser's talk later today at Glue, shows the big names that make up this exclusive club.