EnKoDeur-Mixeur (EKD) is an open source software which makes videos, pictures and audio post-production. It can be also used to convert videos in many formats. It is written in python and use the PyQt4 bindings.
BlenderAVC allows footage from an AVC and HDV camcorder to be pulled into Blender3D (Sequence Editor) without transcoding by generating AviSynth scripts. It also batch-generates proxy images to make it easier to edit the footage on older machines.