Ticket Systems
Open-source ITSM platforms and their ecosystems

KIX
ActiveITSM and service management platform derived from OTRS, developed by cape IT GmbH, focused on asset management and CMDB.
PerlGNU AGPL v3.0

OTOBO
ActiveOpen-source OTRS fork by Rother OSS with modern Docker deployment, Elasticsearch integration, and an active development roadmap.
PerlGNU GPL v3.0

OTRS Community Edition
InactiveThe original open-source ITSM platform (retired in 2021). Foundation for Znuny, OTOBO, and KIX forks.
PerlGNU GPL v3.0

Zammad
ActiveModern, Ruby-based open-source helpdesk and ticketing system with a beautiful web UI, REST API, and Elasticsearch-powered search.
RubyGNU AGPL v3.0

Znuny
ActiveOpen-source fork of OTRS Community Edition. A Perl-based ITSM and helpdesk system with a rich ecosystem of .opm packages.
PerlGNU AGPL v3.0