Swift is part of the larger family of OpenStack. Swift should provide (haven't verified this myself) better integration with all of the other OpenStack components (Keystone, Cinder, Neutron, etc.).
Here are good overviews:
* http://docs.openstack.org/developer/swift/
* https://swiftstack.com/blog/2012/09/16/globally-distributed-...
And how Rackspace runs it at scale;
* https://www.openstack.org/summit/openstack-summit-hong-kong-...