Web Video Downloader is an online video download extension that supports almost all popular online video sharing websites at home and abroad, including YouTube,Google Video,MySpace, Youku, Tudou,6cn, and even Japan's ニコニコ,Mixi, etc., the list is long, and I won't list them here. In addition to the Flv format Video commonly used in video sharing websites,Web Video Downloader also supports swf, wmv, asf, avi, mov, rm, rmvb video formats.