Video players

MPlayer – free and open source, cross-platform media player

QMPlay2 – free and open source, multiplatform video and audio player which can play most formats and codecs

Celluloid – free and open source, simple media player that can play virtually all video and audio formats, GTK+ frontend for mpv

SMPlayer – free and open source media player with built-in codecs, with support for Youtube for Windows and Linux

VLC – free and open source cross-platform powerful multimedia player which plays most multimedia formats