Odoo is probably one of the most wellknown open source ERP on the market. Many native addons are available within the Community edition: HR, Accounting, MRP, Project Management and so much more.
Integrated for many industries
Medical devices - banking - accounting - services - manufacturing such as watchmaking, food industry
Dolibarr is ideal for SMEs and provides all the necessary features to run a small business easily and effectively. We have started with this solution before switching to Odoo.
Zentao is focusing on Project Management, including methodology Scrum, the most popular of Agile methods. Very friendly interface and responsive to any device.