|Logo from pidgin.im|
First, you'll notice that Pidgin does not hook into Office Communicator out of the box. You need a third party extension for this to happen. Meet the Sipe project (http://sipe.sourceforge.net/). You simply install Sipe, start up Pidgin and add your Office Communicator account and credentials. It's as simple as that.
To install Sipe, just drop to the command line and execute (on Ubuntu):
sudo apt-get install pidgin-sipe
For email/calendar support, it's a little tricky. First, install Evolution Mail/Calendar using the Software Installer (or apt-get, yum, etc.) If you are using a recent version of Exchange then great, it will hook into the Outlook Web Access - not ideal, but it works. If you are like me and your company hasn't upgraded Exchange since the dawn of time then you have a little more work ahead of you.
My company uses Exchange 5.5, which is really, really old. It's so old that Evolution doesn't officially support it. However, there is a MAPI add-on that is available to make Evolution work with Exchange. After Evolution email and calendar is installed, execute the following command to install the MAPI extension: sudo apt-get install evolution-mapi
The MAPI extension for Evolution gives you a MAPI Exchange option as a Server option when setting up your email. Simply put in your Exchange email information (you can get this from inspecting your Outlook email account). Assuming you have everything correct, once you save your account information, Evolution will pull in your email and calendar events down. Contacts will also be synched but only after you open Contacts for the first time (this will take a while).
With Evolution and Pidgen setup, you are one step closer to ditching that Windows desktop and taking off the training wheels. ;)