IM is a software utility that allows users connected to the Internet or a corporate network to send text messages and files between other IM users. Check out the following five most popular instant messengers to to help you communicate across networks and the world.
Pidgin
pid gin is really user friendly and easy to use and it support almost every protocol like amsn, gmail, facebook, yahoo, gaber with pidgin you can config several different protocol account, you can use any account that you configure by going account enable account and choose which account you want to enable but only one problem you can use one account at a time you can download pid gin from ubunru software center
EMPATHY
empathy is ubuntu default messaging software which support text, voice, and video and file transfer, Empathy is a multi-protocol instant messaging client for Ubuntu Linux with support for Google Talk (Jabber/XMPP), MSN, IRC, Salut, AIM, Facebook, Yahoo!, Gadu Gadu, Groupwise, ICQ and QQ empathy is by default insatlled in ubuntu so no need to install
Kopete
Kopete also features tools to enhance your instant messaging experience, such as message encryption, archiving, and many other fun and useful effects. kopete support several protocal like AIM, Yahoo, ICQ, MSN, and Jabber. Advanced features and additional protocols are available as plugins you can download it from ubuntu software center
Psi plus
This is the full feature internet messaging software for ubuntu user Psi is free, lightweight, open source instant messaging client for Ubuntu Linux designed for Jabber IM network. Psi IM client support and localizations, easy file transfers, customizable icon sets, and many other great features.
Available in ubuntu software center
Emesene
Ubuntu Linux operating system. Its goal is to replicate the functions of the official Windows Live client in a simpler, cleaner and easier to use interface.emesene tries to be a simple but feature complete program that allows to chat using MSN and Jabber based networks. Emesene available in ubuntu software center