TheoraSoftwarePlayers

Multi-platform

• 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

Windows

• DirectShow filter: Adds support for Ogg Vorbis, Ogg Speex, Ogg Theora, Ogg FLAC, and native FLAC to any DirectShow-compliant player such as Windows Media Player and BSPlayer
• Visonair.tv Player: Freeware player - Plays Ogg Vorbis and Theora streams
• Acquire Digital Signage and Kiosk Software: Plays back all ogg media using the included DirectShow filters.

Linux/BSD

• 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

See also

• Theora Hardware: List of hardware-players supporting Ogg Theora
• TheoraSoftwarePlayers: List of media players that can play Ogg Theora
• TheoraSoftwareEncoders: List of software that can encode to Ogg Theora
• TheoraDecoders: List of decoder implementations
• TheoraEncoders: List of encoder implementations
• List of Theora videos: Get some files to see what the codec's like
• Games that use Theora: List of known games that use Theora
• TheoraTestsuite: Different samples to test player compliance