UVdesk

UVdesk is an open-source help desk solution with a strong focus on e-commerce integrations, particularly for Magento and Shopify. It provides multi-channel support, a knowledge base, and community-driven extensions.

It can be self-hosted for free or used as a cloud service. It targets e-commerce merchants looking for a cost-effective, customizable support system that integrates natively with their store. It scores decently as a niche open-source option for online retailers who want to avoid monthly SaaS fees and have the technical ability to manage their own installation and customization.