Google Wave has moved to the Apache Foundation:
http://incubator.apache.org/wave/
The cwave project is a complete wave federation protocol implementation in C.
It depends on protobuf-c, a C implementation of Protocol Buffers (a google project). A gentoo ebuild for protobuf-c is available in the cwave source tree. Fedora Core and Debian/Ubuntu packages are a possibility. cwave is based on the jabberd2 code.
This implementation is an alpha-quality wave federation server (protocol 0.2). C code allows integration with the widest possible range of hardware and application stacks. Cwave stretches the limits of what wave can do, such as internet non-linear video editing.