We haven't integrated a dedicated chat service into the forum system but pairs of forum members can exchange Private Messages or email if both of them enable it. See
How do I send a Private Message to another member? and
How do I send email to another member? in the FAQ.
You can also connect with other members using popular instant messaging services. Put your AIM, Yahoo!, Skype, or other IM name in your
user profile and look for that information in the profiles of other users. Click on a user's forum name to see their user profile. See
How do I use instant messaging with another member? in the FAQ.
Members are also welcome to establish their own connections outside of Marrowforums and to use other individual or group chat services, of course. You can use a Private Message or email to make "first contact" and arrange the rest between you.