I need to sync MS Exchange's contacts with my Ruby on Rails application.
Which is the best way? Would you recommend any existing gems for it?
One place to start would be the Exchange Developer Center, where Microsoft links to downloads of the different SDKs, documentation, etc. Understandably, most of the docs and examples will be using Microsoft's .NET Framework and languages.
If you want to connect with Exchange 2007 or 2010, you'll probably find it easiest to use some form of Exchange Web Services (EWS) which you may be able to connect to using Ruby web services frameworks like SOAP4R, WSO2, etc.
For Exchange 2003 and earlier, you're much more limited; and programming CDO through Ruby's win32ole is not going to be pretty or fun.
Perhaps https://rubygems.org/gems/exchanger exchanger gem will help you.
Ruby library for accessing Microsoft Exchange using Exchange Web Services. This library tries to make creating and updating items as easy as possible. It will keep track of changed properties and will update only them.
I tested viewpoint gem and it works. Be sure to follow wiki page for instructions, because readme is a little bit deprecated.
perhaps using win32ole?
Updating this thread a bit, 5 years later: this gem looks promising, starting to test it right now: https://github.com/WinRb/Viewpoint
来源：https://stackoverflow.com/questions/3556647/accessing-microsoft-exchange-server-from-ruby