PennMUSH is a MUD server that is often used for running social or role-playing games, with an extensive internal programming language. It runs on Unix systems, Windows, and MacOS.
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.