OpenStack is a collection of libraries for simplifying communication-based applications and testing. This includes open-source Modbus RTU, Modbus/TCP and Modbus/UDP stacks.
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.