Video
mplayerplug-in is a browser plugin that uses mplayer to play digital media from websites.
More Info 
Developer: mplayerplug-in-developers
License: GNU General Public License (GPL)
Operating System: Unix, Linux
XviD is an open source MPEG-4 video codec, written in C with assembler optmizations for quality and speed.
Developer: xvid.org
License: GNU General Public License (GPL)
Operating System: linux
Gecko Multimedia System is a complete media solution, able to play almost all media types and supports scheduled tv-recording from online tv-guides.
Developer: Erik Westlund
License: GNU General Public License (GPL)
Operating System: All POSIX (Linux/BSD/UNIX-like OSes)
Player is a movie player which runs on many systems and plays most known video and audio formats.
Developer: MPlayer
License: GNU General Public License (GPL)
Operating System: OS Independent (Written in an interpreted language)
Edit your avi, mpeg and nuv.
Developer: avidemux
License: GNU General Public License (GPL)
Operating System: All POSIX (Linux/BSD/UNIX-like OSes), Linux, Other
FlasKMPEG.
Developer: flaskmpeg
License: GNU General Public License (GPL)
Operating System: All 32-bit MS Windows (95/98/NT/2000/XP)
VirtualDubMod is based on the famous video editing software VirtualDub by Avery Lee.
Developer: virtualdubmod
License: GNU General Public License (GPL)
Operating System: 32-bit MS Windows (95/98), All 32-bit MS Windows (95/98/NT/2000/XP)
ffdshow is DirectShow and VFW codec for decoding/encoding many video and audio formats, including DivX and XviD movies using libavcodec, xvid and other opensourced libraries with a rich set of postprocessing filters.
Developer: ffdshow
License: GNU General Public License (GPL)
Operating System: All 32-bit MS Windows (95/98/NT/2000/XP)
Desktop video processing and capture application (Win32).
Developer: virtualdub.org
License: GNU General Public License (GPL)
Operating System: 32-bit MS Windows (95/98), All 32-bit MS Windows (95/98/NT/2000/XP)
This is DVD authoring program with nice and clean GUI.
Developer: atom-project
License: GNU General Public License (GPL)
Operating System: All POSIX (Linux/BSD/UNIX-like OSes), Linux