OpenChange intends to provide a portable implementation of the Microsoft Outlook and Microsoft Exchange protocols. That is, it provides the client and server sides of the Microsoft Exchange RPC (MAPI) protocols.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.
Two whitepapers have been released on the OpenChange Web site:
"MSRPC Approach between Exchange and Outlook" and "Practical Application
of sniffing methods, Opensniff".