Solvvy - Highly intelligent customer support self-service solution via AI/ML/NLP science
Freshservice - Freshservice: the one-stop cloud solution for all your IT management needs.
Whatfix - Whatfix Enterprise: Enhancing self-service capability of any web product
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
phpMyFAQ - phpMyFAQ is a world’s most popular mobile-friendly, feature-rich and open-sources FAQ software that uses PHP 5.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.