Great Downloader easy to use can convert into multiple file formats. Fast and impressive
QLab - QLab, Live show control for Mac OS X.
Video DownloadHelper - Browser extension to download videos from the Web
Cue Player - Cue Player software for theater sound and lighting
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.
Trigger Audio and Video Playback - Audio and video cue player for broadcast and live performance.
Youtube Video and Audio Downloader - Download YouTube videos in all available formats and extract the original audio files.