The Great American Hackathon from Sunlight Labs is coming December 12-13. Unlike most API-hacking events, this one is taking place all over the United States, in at least seven cities. The idea is to encourage developers to work together and jump start work on projects using government data.
Here is a list of 93 events APIs from ProgrammableWeb including the Eventility API and the popular Eventful API. We also list 46 Eventful mashups. Developers who want to integrate services such as event lists, ticketing and event management for applications will find this list useful.
Last December, Senzari launched the MusicGraph music recommendation and data access engine as well as the new MusicGraph API. Earlier this month, Senzari opened the MusicGraph API to the public, unveiling the API at the first-ever annual SXSW Music Hackathon Championship. Among the apps included in the list of overall grand prize finalists is Party Play which uses the MusicGraph API to create "a dynamic DJ for parties."