Apache Wave is the project where wave technology is developed at Apache. Wave in a Box (WIAB) is the name of the main product at the moment, which is a server that hosts and federates waves, supports extensive APIs, and provides a rich web client. This project also includes an implementation of the Wave Federation protocol, to enable federated collaboration systems (such as multiple interoperable Wave In a Box instances).
"Wave on App Engine- Walkaround - Wave on App Engine
Walkaround is a variant of Wave, based on the Apache Wave code base, that runs on App Engine. Walkaround can import waves from wave.google.com to allow users to keep working with their data after wave.google.com is shut down."