BlueSeer - BlueSeer is the best ERP software for your business requirements because it comes with no trial version, and it is completely free to use.
Dolibarr - Dolibarr ERP CRM is an Open Source software package for small, medium or large companies, freelancers or foundations to manage business. It's a PHP project built by modules addition (invoice, proposal, contact, stock, order, hr, agenda. .
inoERP - inoERP is an open source php based enterprise management system.
Odoo - An all-integrated business app suite to unleash your growth potential.
Metasfresh - Metasfresh is open-source software that provides an ERP module for your business, and it is easy to use and comes with that Java integration.
EasyErp - EasyERP is a fast and flexible open source ERP / CRM / HRM software, perfect for small and medium business. Both cloud and on-premises versions are available.