Q. Can I install and run Pidgin instant messaging client under Mac OS X operating system?
A. Short answer - yes, if you can compile and install X server / GTK+ on Mac OS X.
Long answer - Pidgin (Gaim) is a multi-platform instant messaging client. The software has limited support for many commonly used instant messaging protocols. You need to compile and install an X server, GTK+ and its dependencies yourself. You will not get native aqua interface including installer. I strongly suggest Adium, which is a free instant messaging application for Mac OS X that can connect to AIM, MSN, Jabber, Yahoo, and more.