HelpScout - Help Scout is a simple, straightforward way to provide excellent support

statuspage - A simple self-hosted status page site with an API written in Django under the BSD license.

Zendesk - Zendesk is a beautiful, lightweight help-desk solution.

YUNO - YUNO is a web data driven company focussed on solving customer challenges in web data discovery and extraction space.

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

FreshStatus - Better status pages in 1-click, FREE FOREVER