Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
Freshservice - Freshservice: the one-stop cloud solution for all your IT management needs.
OpenSupports - Simple open source ticket system with user system and modern design.
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
ServiceNow - ServiceNow automates and manages global enterprise service relationships. Create a single system of record for enterprise services, automate manual tasks, consolidate legacy ITIL systems.
SolarWinds Service Desk - An IT service management (ITSM) solution that understands what it takes to successfully manage your employee services. Try Solarwinds Service Desk for free!