Ximian's mixed source strategy Ximian's proprietary "Lucy" connector lets its GPL'd "Evolution" PIM speak with Microsoft Exchange servers. I don't quite understand why Ximian decided to GPL the PIM client and make the connector proprietary. A good PIM (or even a bad Outlook clone PIM) is not something that Free Software/Open Source would tend to create, making it a prime candidate for proprietary software. But an adaptor seems right up Open Source's alley, and would help commoditize the mail server under the PIM client, which is good for a proprietary PIM vendor. There is no similar benefit for a proprietary adaptor vendor for commodity OS PIMs. Making GNU/Linux desktops more viable in Microsoft server environment seems to be doing things the hard way, and keeping adaptors (which OSS tends to be OK at making) proprietary while GPLing bad GUI PIMs (which OSS is really bad at making) strikes me as being backword.

But it's easier now to have a GNU/Linux desktop in an all MS shop, which I'm sure will be good news for some. Personally, I'm bracing for the cataclysm when the Chicago Business School updates it's horrible IMP system to something that works with Outlook calendering. The school just suffered it's third Outlook based virus attack in about one month, so it's tieing itself to that God-forsaken platform more closely. *Sigh*