Camunda - The Universal Process Orchestrator
Freshservice - Freshservice: the one-stop cloud solution for all your IT management needs.
jBPM - jBPM is a flexible Business Process Management (BPM) Suite.
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
ProcessMaker - ProcessMaker is an easy to use BPM and workflow software solution. It is used to design, automate, and deploy business processes of any kind.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.