- [ITFlow](https://itflow.org) - Client IT Documentation, Ticketing, Invoicing and Accounting Web Application for MSPs (Managed Service Providers). ([Demo](https://demo.itflow.org), [Source Code](https://github.com/itflow-org/itflow)) `GPL-3.0``PHP`
- [MantisBT](https://www.mantisbt.org/) - Self hosted bug tracker, fits best for software development. ([Demo](https://www.mantisbt.org/bugs/my_view_page.php), [Source Code](https://github.com/mantisbt/mantisbt)) `GPL-2.0``PHP`
- [osTicket](https://osticket.com/) - Manage, organize and archive all your support requests and responses in one place. ([Source Code](https://github.com/osTicket/osTicket)) `GPL-2.0``PHP`
- [OTOBO](https://otobo.de/en/) - Flexible web-based ticketing system used for Customer Service, Help Desk, IT Service Management. ([Demo](https://otobo.de/en/open-source-ticketing-system/#demos), [Source Code](https://github.com/RotherOSS/otobo)) `GPL-3.0``Perl/Docker`
- [OTOBO](https://otobo.io/en/) - 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)) `GPL-3.0``Perl/Docker`
- [Roundup Issue Tracker](https://www.roundup-tracker.org/) - A 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. ([Source Code](https://www.roundup-tracker.org/code.html)) `MIT/ZPL-2.0``Python/Docker`
- [Trudesk](https://trudesk.io/) - Trudesk is an open-source help desk/ticketing solution. ([Source Code](https://github.com/polonel/trudesk)) `Apache-2.0``Nodejs/Docker`