psi: Psi (Qt Jabber client) psi: psi: Psi is a free instant messaging application designed for the XMPP psi: network (including Google Talk). Fast and lightweight, Psi is fully psi: open-source and compatible with Windows, Linux, and Mac OS X. psi: psi: With Psi's full Unicode support and localizations, easy file psi: transfers, customizable iconsets, and many other great features, psi: you'll learn why users around the world are making the switch to free, psi: open instant messaging. psi: