It's not a question of "speaking" the proprietary stuff, but also of interpreting it correctly and making sure the software acts on the data in a useful way. Calendaring is a difficult problem and not really interesting to the "typical OSS hacker".
There's progress being made though, see http://www.openchange.org/
This hack only works on some versions of some drivers. On my system with Intel graphics and recent drivers it completely crashes the X server after some time. Oh, and it's slower too
Having to look up stuff in the manual is DRM?
Microsoft supported Moonlight? All I've seen is some tech-demo thing which craps out on 90% of the Silverlight content I've found. At least Flash works...
"If I do not want others to quote me, I do not speak." -- Phil Wayne