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.
This release fixes numerous memory leaks, improves MAPI operations support, and provides a very preliminary (but working) OpenChange server implementation.