Odoo Community Edition

Odoo Community Edition is a highly modular open-source ERP system. It offers a core set of applications including accounting, sales, CRM, inventory, and project management. Its app store provides numerous additional modules, though many advanced features are reserved for the paid Enterprise version. It's suitable for small to medium-sized businesses needing a flexible and customizable solution.

The open-source nature allows for community support and self-hosting, reducing licensing costs. It's known for its modern interface and extensive integration capabilities.