During Google I/O 2010, Google announced a new data API which can be used to create lightweight clients or applications that can act on behalf of the user through OAuth. Microwave was initially designed (in early january) as a read-only client for Google Wave powered by the reverse engineered JSON wire client/server protocol, equally targeting mobile and desktop. Since May, the aim of the project has shifted to produce an awesome mobile client.

This project has moved over to github:

http://github.com/antimatter15/microwave

However, if you still want the old code:

http://code.google.com/p/microwave/source/checkout