Open Source Ticketing Software
Found 11 self-hosted alternatives in this category.
Bugzilla
General-purpose bugtracker and testing tool originally developed and used by the Mozilla project
Frappe Helpdesk
Helpdesk software which helps you streamline your company's support, offers an easy setup, clean user interface, and automation tools to resolve customer queries efficiently
FreeScout
Email-based customer support application, help desk and shared mailbox (alternative to Zendesk and Help Scout). ([Demo](https://demo.freescout.net/login), [Source Code](https://github.com/freescout-help-desk/freescout))
ITFlow
Client IT documentation, ticketing, invoicing and accounting for MSPs (Managed Service Providers). ([Demo](https://demo.itflow.org), [Source Code](https://github.com/itflow-org/itflow))
MantisBT
Bug tracker, fits best for software development. ([Demo](https://www.mantisbt.org/bugs/my_view_page.php), [Source Code](https://github.com/mantisbt/mantisbt))
OTOBO
Flexible web-based ticketing system used for customer service, help desk, IT service management. ([Demo](https://otobo.io/en/service-management-plattform/otobo-demo/), [Source Code](https://github.com/RotherOSS/otobo))
Roundup Issue Tracker
Simple-to-use and -install issue tracking system with command-line, web, REST, XML-RPC, and e-mail interfaces. Designed with flexibility in mind - not just another bug tracker