The Guild Wars 2 API C/C++ Library Project provides methods for sending and receiving data from the Guild Wars 2 API's servers in C and C++. Methods for handling Items and Guilds are currently missing.
At the The Next Web Hackathon in Amsterdam, developers played with a lot of new APIs. One that caught our attention is the Gbanga Puppetmaster API. Gbanga is a location-aware gaming platform, intended for use with games where walking around within the real world matter. It's released one game, Gbanga Famiglia, a mobile phone-based app using a theme of mafia families taking over areas and finding loot. Much more exciting, however, is its API, which allows for quests within Famiglia, and other, separate location-based games.