Hards said more work is being done on the client side and "we have code for the server", but estimates another 12 months of development is required to produce an OpenChange server ready for production.

"Why OpenChange? We are not just trying to do mail, but all the time management stuff," he said.

"You should be able to change out some of your clients, or introduce new clients, and you don't need to change the backend. You could use an Exchange server or OpenChange server, Windows client or Linux client. Potentially, you might run either -- or some combination -- depending on users' needs."

The client side C++ libraries were contributed to by a Google Summer of Code student project and Hards said the code is "maturing well".

"Out of 120 RPCs we implement about 88 and they are mostly right," he said. "80 have unit tests behind them and French developer Julien Kerihuel coded most of it. I coded about 1 percent of it. A French company has done some good work along with the Evolution guys from Novell."