Enterprise Resource Planning (ERP) Software
Apache OFBiz Enterprise software framework
ADempiere Business solution offering ERP, CRM CM functionality,POS
ERP5 Mission critical software for industrial organisations and government agencies
WebERP Complete web based accounting ERP system for SMEs
PostBooks Full-featured, fully-integrated accounting, ERP, and CRM system
Openbravo Designed with broad business functionality
Compiere ERP CRM solution for small and medium-sized enterprises
Opentaps Based on Apache OFBiz
Dolibarr Compact ERP CRM
OpenERP A complete ERP and CRM modular system
You can download it all in sourceforge.nst