Pidgin - Pidgin is an easy to use and free chat client used by millions. Connect to AIM, MSN, Yahoo, and more chat networks all at once.
Freshservice - Freshservice: the one-stop cloud solution for all your IT management needs.
Adium - Adium is a free instant messaging application for Mac OS X that can connect to AIM, MSN, Jabber, Yahoo, and more.
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
Gajim - Full featured and easy to use Jabber client
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.