There are many Services in Fedora. Many of these have an interface that we can query and get back information as JSON data. There is documentation here about both the services and the client modules that can access them.
FAS is the Fedora Account System. It holds the account data for all of our contributors.
The Package Database holds information about packages in Fedora. It currently has a developer-centric view of packages that concentrates on who the owner is of a particular package.
Plans to add an end-user view to packages is ongoing.
Bodhi is used to push updates from the build system to the download repositories. It lets packagers send packages to the testing repository or to the update repository.