statuspage - A simple self-hosted status page site with an API written in Django under the BSD license.
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
YUNO - YUNO is a web data driven company focussed on solving customer challenges in web data discovery and extraction space.
LiveAgent - LiveAgent is a fully-featured web-based live chat and help desk software. It harnesses the power of a universal inbox, real-time live chat, built-in call center, and a robust customer service portal. Start your free 1 month trial today!
Yonyx - Decision tree driven Interactive guides for customer service
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.