Helpdesk – ServerOK

OpenSource Helpdesk

FreeScout – Open Souce ZenDesk clone. PHP/Laravel. Very active project.
https://www.uvdesk.com/en/ – Open Source Helpdesk software
https://osticket.com/ – Free Open Source Helpdesk.
OpenSupports.com – Free Open Source Helpdesk.
https://zammad.org – Open Source helpdesk in Ruby On Rails. https://github.com/zammad/zammad
https://otrs.com/ – Written in Perl. Open source version with Limited features. https://github.com/OTRS/otrs
https://www.uvdesk.com – Open Source version available https://github.com/uvdesk/community-skeleton
https://glpi-project.org/ – open source tool to manage Helpdesk and IT assets!