Web video downloader for Firefox, a free intelligent Firefox extension, can capture videos, download FLV videos from Youtube and other sites. It can download videos with one-click of various formats including FLV, SWF, WMV, AVI, MOV, RM, RMVB, etc. The video downloader also synchronizes new videos with the video download page, and always offers hottest video information. It is a really good video download assistant for offline video enjoyment.