MPlayer is a movie player that can play many formats. It supports VideoCD, SVCD, DVD, 3ivx, DivX 3/4/5, WMV and H.264. It also supports many different encoding and fonts for displaying status information and subtitles.
SMPlayer intends to be a complete front-end for Mplayer, from basic features like playing videos, DVDs, and VCDs to more advanced features like support for Mplayer filters and more. One of the main features is the ability to remember the state of a played file, so when you play it later it will resume at the same point and with the same settings. SMPlayer is developed with the Qt toolkit, so it's multi-platform...
XBMC is a media player and entertainment hub for digital media. XBMC functions as a standard media player application for your computer or as the perfect companion for your Home Theater PC. It supports a wide range of remote controls, and combined with its beautiful interface and powerful skinning engine, XBMC feels very natural to use from the couch and is the ideal solution for your home theater.
iTunes is an audio player for playing and organizing digital music files, and purchasing digital music files in the FairPlay digital rights management format. The iTunes Music Store is the component of iTunes through which users can purchase digital music files from within iTunes.
K-Multimedia Player is a media player software for Microsoft Windows which can play a large number of formats including VCD, DVD, AVI, MKV, Ogg, OGM, 3GP, MPEG-1/2/4, WMV, RealMedia, FLV and QuickTime.
xine is a multimedia player. It plays back CDs, DVDs, and VCDs. It also decodes multimedia files like AVI, MOV, WMV, and MP3 from local disk drives, and displays multimedia streamed over the Internet. It interprets many of the most common multimedia formats available. All those features come in a reusable library (xine-lib) which can be embedded in your applications.
JetAudio is integrated multimedia software made of a single compact rack. Not only does it play various music and video files, it also has features such as CD burning, recording, and conversion to other file formats.