Zammad

Web-based help desk and ticketing across email, chat and social.

Zammad is an open-source help-desk and ticketing system built with Ruby on Rails and a JavaScript frontend, designed for customer support, ITSM, and shared inboxes. It unifies tickets from email, chat, phone, and social channels, with SLAs, triggers, text modules, full-text search, and a knowledge base. It is notable for its mature feature set, granular permissions, and extensive REST API for integrations.