What are some alternatives?
youtube-dl - A small command-line program to download videos from https://alternativeto.
FlashGot - FlashGot is a browser extension for Mozilla Firefox that is designed to make it easy to download a whole batch of files in one go. The extension is open source and free to use, but it is no longer compatible with the most recent version of Firefox.
Youtube Video and Audio Downloader - Download YouTube videos in all available formats and extract the original audio files.
ClipGrab - vanbittern entwickelt individuelle Weblösungen.
SaveFrom.net - Free Online service to Download YouTube videos at one click! The best YouTube Downloader supporting fast and easy vimeo, Facebook and Dailymotion video Download and much more!
YouTube Center - Status of YouTube Center. As of many of you know. I have not been actively developing on YouTube Center and there's a good reason for that. I have acquired a full time job, which leaves not much time for development.