youtube-dl - A small command-line program to download videos.
Free YouTube to MP3 Converter - Best YouTube to MP3 Converter of 2019. Any format, any quality, ad-free. Easy YouTube playlists downloads. Loved by users since 2006.
4k Video Downloader - 4K Video Downloader is a software program that helps people download video files from sites such as Facebook, YouTube and Dailymotion.
Youtube Video and Audio Downloader - Download YouTube videos in all available formats and extract the original audio files.
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.
yt2mp3.org - Free online YouTube to MP3 Converter