Universal Media Server - Universal Media Server allows you to host your entire library of video, music, and pictures, and broadcast them conveniently to a wide variety of different devices.
VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
Kodi - Kodi is an award winning free and open source media player that got its start on the Xbox console.
MX Player - Powerful video player with advanced hardware acceleration and subtitle support.
Veso - Veso is an open source media server. An emby/jellyfin fork that will move to a js react framework and focus on remote/rclone mounted media rather than local storage.
VPlayer - VPlayer - a free music player for VKontakte.