Quoddy is part of the Fogcutter suite of tools for building intelligent applications.
Basically, Quoddy is a sort of "mini Facebook" like social-networking interface. It builds on the APIs for social-graph management, activity-stream, activity profiling, tagging, etc. Provides the front-end for managing connections and for letting users provide information about themselves, their interests, etc. But unlike Facebook, no silly Pirates vs. Ninjas or Farmville stuff.