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

Supportbench - Supportbench is a customer service solution that delivers on your promises to customers.

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

Front - The platform for exceptional customer service at scale.

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

IncidentMonitor - Service desk software with self-service web portal support