Veejay is a visual instrument and real-time video sampler. It allows you to "play" the video like you would play a piano. While playing, you can record the resulting video directly to disk (video sampling). Veejay can be operated live by using the keyboard (which is completely user definable) or remotely over TCP/IP. Veejay can be used to manipulate video in a realtime environment such as visual performances or for (automated) interactive video installations.
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.
iVideo is multitrack video editing software, created in Cocoa (Objective-C) and using QuickTime. It was developed for all general video purposes, and to include all of the features of QuickTime Pro and iMovie. It is almost complete; you can import video from digital cameras (using FireWire) or from any QuickTime format supported file, then edit, modify, and mix them, and apply any video effect on or between them. You can then export them to any QuickTime supported format.
kmenc15 is an MEncoder frontend, generally designed to be a VirtualDub replacement for Linux. It is most useful for editing and encoding large, high-quality AVIs capped from TV. It allows cutting and merging at exact frames, applying any MPlayer/MEncoder filter, with previews. It does not support opening MPEGs.