Bookmark : Free Editing Tools

Avid Free DV (Microsoft Windows, Mac OS X)
AVIedit (Microsoft Windows)
AviTricks classic
Clesh (Java on Microsoft Windows, Mac OS X, Linux)
Zwei Stein
Windows Movie Maker (Microsoft Windows)

CleshLoad (Java on Microsoft Windows, Mac OS X, Linux)
TMPGEnc (Microsoft Windows)
Windows Media Encoder (Microsoft Windows)
MPEG Stream (Microsoft Windows, Mac OS X)

Blender (software) (cross-platform)
HyperEngine-AV (Macintosh)
Jahshaka (Cross platform)
LiVES (Linux)

Avidemux (cross-platform)
AviSynth (Microsoft Windows)
FFmpeg
MediaCoder
MP4Box
Nandub
VirtualDubMod (Microsoft Windows) (based on VirtualDub, but with additional input/output formats)