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1. A domain name
2. An ssl certificate from a trusted source (in this case, we use StartSSL) (Recommended, but not necessary whilst you test federation)
3. An XMPP server

Most of the instructions for setting up these things are found in the following child pages:

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The utility of waves is greatly enhanced if they can be federated in the sense that they are shared between users from different organisations, hosted by different service providers across the Internet. This is accomplished by the Apache Wave federation protocol, a server-to-server network protocol between service providers, supporting low-latency, concurrent updates to conversations ("live typing") and domain authentication.

STOP.

IF YOU ARE JUST TRYING TO SETUP FEDERATION ON YOUR SERVER FOLLOW THE LINKS ABOVE. IF YOU HAVE A 'SPECIAL' SETUP, OR WANT TO UNDERSTAND HOW IT WORKS, YOU MAY CONTINUE BELOW THIS LINE.

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Here are some resources that explain the protocol and show how to run a federated "Wave in a Box" wave server:

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