https://jellyfin.org/docs/general/about
Jellyfin is a Free Software Media System that puts you in control of managing and streaming your media. It is an alternative to the proprietary Emby and Plex, to provide media from a dedicated server to end-user devices via multiple apps. Jellyfin is descended from Emby's 3.5.2 release and ported to the .NET Core framework to enable full cross-platform support. There are no strings attached, no premium licenses or features, and no hidden agendas: just a team who want to build something better and work together to achieve it. We welcome anyone who is interested in joining us in our quest!
Jellyfin seeks to continue development of the original Emby project with a Free Software ethos. It is committed to bringing all its users access to the best possible Media System, developed entirely by a community of volunteers who contribute code, documentation, translations, and support to the project.