Brutus is a new Open Source MS Exchange connector. It is the answer to the authors frustration at the lack of platform independent access to the MAPI framework.
MAPI is a requirement if you intent to develop an application that integrates in an Exchange infrastructur on an equal footing with MS Outlook. MAPI is Windows-only too.
Brutus works by wrapping the native Microsoft MAPI library in a (large) set of CORBA interfaces. Using CORBA makes the client part of Brutus platform and implementation language independent. The Brutus server part must be installed on some Windows server, preferably the Exchange server due to performance issues.
Basing Brutus upon a CORBA wrapping of MAPI makes it well suited to provide access to all versions of MS Exchange from 5.5 onwards. WebDAV based solutions, such as the Evolution Connector from Novell, has a range of WebDAV-caused limitations. One of those limitations is the inability to support Exchange 5.5. Additionally, the available feature-set of WebDAV is smaller than that of a MAPI/Brutus based application as well.
Brutus is released under the terms of the GPL and can be download, with working sample code here.