Redd is a Ruby Wrapper written for the Reddit API. It is intended to be extensible, have ease of use, and bring simplicity to using the Reddit API. Redd is authored by Avinash Dwarapu and is meant to be accessible and fun.
Keek, social video network, recently announced the release of the Keek API. Alongside the API launch, Keek established a developer portal that includes tools and resources to assist developers in integrating Keek with third party applications. The Keek API grants developers access to public keeks (i.e. 36 second video updates), search, user profiles, klusters, and more.
At its annual F8 developer conference, Facebook yesterday announced the launch of Graph API 3.0 as well as enhanced developer app review. The third version of the company's Graph API contain a number of changes to Facebook Login and the /comments edge and what data is returned.
The Swipp API allows developers to integrate Swipp's "Social Intelligence" into their sites and applications. Public information is not available on the API; interested parties are asked to email email@example.com. Once available the APIs will "make it possible for people to interact around any topic imaginable."