You will need to download and install the Adium client for Mac OS X from http://www.adiumx.com/.
1. Launch the Adium client. Upon first run, you will be presented with the Preferences window.
2. In the Preferences: Accounts window that appears, click the + sign in the bottom left-hand corner of the window and select Jabber.

3. In the Jabber ID field, enter yourNetID@jabber.duke.edu (replacing yourNetID with your Duke NetID). Don't enter a password at this time.
4. Select Automatically connect on launch if you want AdiumX to connect to the Jabber system when launched.

5. Click the Personal tab located at the top of the window and enter your name in the Alias field. Be aware that you can switch the icon but it will not be visible to other Jabber users, including those on Adium.

6. Click the Options tab at the top of the window and in the Connect Server field enter jabber.duke.edu. In the port field, enter 5222 and check Use TLS.

Click OK. AdiumX should connect to the Jabber server and prompt for your password.
Adium refers to people you instant message with as "buddies." In order to communicate with someone you first must enter them into your buddy list.
Adium allows you to organize your buddies into different groups (e.g. family, friends, co-workers etc). This can be useful if you maintain a large list of buddies.