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.
When planning an event, aside from all the fun stuff like the programme, the décor and the like, the bottom line is getting people to turn up; and no-one's going to make an appearance if they don't even know it exists. So marketing the event is key, and that's where evvnt comes in. It's an online event marketing service that focuses on getting the word out there by broadcasting and publishing a user's event to multiple event listing sites. The evvnt API makes this functionality available to be integrated with other sites and applications.