Linux open source, surpisingly complete video editor.
Ranked in these QuestionsQuestion Ranking
Pro Open Source
Kdenlive is licensed under GPLv2, and built on top of other open source projects like FFmpeg.
Pro Surpisingly complete
Although this editor is not up with the top of the professional pack of editors, it certainly packs a powerful punch, and should provide enough features for amateur montages, ranging from alpha manipulation, to multiple audio and video live track editing.