Psi is the premiere Instant Messaging application designed for Microsoft Windows, Apple Mac OS X and GNU/Linux. Built upon an open protocol named Jabber, Psi is a fast and lightweight messaging client that utilises the best in open source technologies. Psi contains all the features necessary to chat, with no bloated extras that slow your computer down. The Jabber protocol provides gateways to other protocols as AIM, ICQ, MSN and Yahoo!. If you want SSL support, install the qca-tls package.