- VLC Media Player: Open Source media player and streaming server that support virtually every video and audio format
- Xiph Plugins for Real Player/Producer
- Quicktime components for Quicktime 6 and Quicktime 7 – QuickTime and Macintosh OS X plug-ins
- Mplayer: Open Source video player (some limitations). SMPlayer is a front-end which provides mplayer and libraries for different platforms.
- CorePlayer: A multimedia platform for mobile and desktop computer systems
- Cortado: Java applet playing ogg/theora/vorbis
- Mozilla Firefox: Open Source web browser, Theora support since version 3.5 (was 3.1 beta)
- Opera Web browser (closed source freeware), Theora support in experimental builds from 2007-Nov (very buggy), 10.5x versions (official support, but still had problems), and version 10.60 (2010-Jul-01) and newer (should be mature, also supports WebM/VP8 video)
- Google Chrome: Web browser (supports Theora, WebM/VP8 and H264)
- Safari 3.1 and later: if the XiphQT components are installed
- Helix Player - an open source media player for Linux, Solaris, and Symbian based on the Helix DNA Client media engine.
- Totem - a Free Software (GPL-licensed) media player based on xine or GStreamer media engine.
- Xine: a Free Software (GPL-licensed) media player, complete with its own media engine and a long list of supported formats.
Mac OS X
- Xine: a Free Software (GPL-licensed) media player, complete with its own media engine and a long list of supported formats. Supports Darwin/MacOS X (ppc) via the fink project.
- Elmedia Player – media player for Mac, which supports playback of lots of video formats (OGG Theora, WebM (???), proprietary formats), closed source freeware + PRO version
- yxplayer: for-pay video player, which can play Vorbis audio and Theora video. In app store, no jailbreak required.