Akka uses Git and is hosted at Github.
The Akka Maven repository can be found at http://repo.akka.io/releases.
Typesafe provides http://repo.typesafe.com/typesafe/releases/ that proxies several other repositories, including akka.io. It is convenient to use the Typesafe repository, since it includes all external dependencies of Akka. It is a “best-effort” service, and if it is unavailable you may need to use the underlying repositories directly.