Open-source alternatives to Zendesk

2 community-reviewed projects you can use instead of Zendesk.

1. Chatwoot - Chatwoot is an open-source, self-hosted customer engagement suite that brings live-chat, email, WhatsApp, Facebook, Instagram, Telegram and other channels into one shared team inbox. It offers a website chat widget, automations, canned responses, reports and a help-center, and can also be used via Chatwoot Cloud. (Licence: NOASSERTION)
2. osTicket - osTicket is a widely-used, free, open-source support ticket system that turns inquiries from email, phone and web forms into tickets in a simple multi-user web interface, so teams can manage, organise and archive all support requests and responses in one place. (Licence: GPL-2.0)