VirtualDub

( Diese Seite in Deutsch )

The original open source video capturing and processing tool written by Avery Lee without which Avisynth would probably not exist.

http://www.virtualdub.org

You should also try a community modification called VirtualDubMod. It contains many useful new features, and also a built in script editor for AviSynth.

http://sourceforge.net/projects/virtualdubmod/