Swift can integrate with OpenStack, but you can very easily run it stand alone, and many do. It has erasure coding, geo replication, and its a fairly well baked product.

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-...