Vividl - Free video downloader for YouTube and other websites
youtube-dl - A small command-line program to download videos.
Video DownloadHelper - DownloadHelper is a tool for web content extraction.
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.
Nico Nico Douga Downloader - Download anime videos, audio music mp3, thumbnail images, manga from nicovideo.jp
4k Video Downloader - 4K Video Downloader is a software program that helps people download video files from sites such as Facebook, YouTube and Dailymotion.