LiVES is a simple to use yet powerful video effects, editing, conversion, and playback system aimed at the digital video artist and VJ. It runs under Linux, BSD, Mac OS X/Darwin, IRIX, and openMosix. It is frame and sample accurate, can handle almost all types of video, and is fully extendable through plugins and the included plugin builder tool. It can also be controlled remotely using OSC.
KMediagrab is a media grabber and encoder built on top of mplayer/mencoder. It can grab and encode a DVD at the same time (e.g., creating a divx or a videocd file for instance), record a movie or your favourite TV program from your TV-card, or translate a video file from one format to another (e.g., create a realplayer file from a .wmv one).