VLC media player is a highly portable multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, mp3, ogg, ...) as well as DVDs, VCDs, and various streaming protocols. It can also be used as a server to stream in unicast or multicast in IPv4 or IPv6 on a high-bandwidth network. It doesn't need any external codec or program to work. 

Features: 

Free, Open Source and cross-platform 

Independant of systems codecs to support most video types 

Live recording 

Instant pausing and Frame-by-Frame support 

Finer speed controls 

New HD codecs (AES3, Dolby Digital Plus, TrueHD, Blu-

Ray Linear PCM, Real Video 3.0 and 4.0, ...) 

New formats (Raw Dirac, M2TS, ...) and major improvements in many formats... 

New Dirac encoder and MP3 fixed-point encoder 

Video scaling in fullscreen 

RTSP Trickplay support 

Zipped file playback 

Customizable toolbars 

Easier encoding GUI in Qt interface 

Better integration in Gtk environments 

MTP devices on linux 

AirTunes streaming 

New skin for the skins2 interface