Great Downloader easy to use can convert into multiple file formats. Fast and impressive
Video DownloadHelper - Browser extension to download videos from the Web
Coconut - Coconut is a cloud video encoding solution, built for developers.
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.
Opencast - Opencast is an open source solution for automated video capture and distribution at scale.
Youtube Video and Audio Downloader - Download YouTube videos in all available formats and extract the original audio files.
Telestream - Telestream offers video capture, encoding, transcoding, and network-based delivery.