Videomanager is a Web-based video manager. It's not a Youtube/Vimeo clone, it just provides the core functionality of uploading, converting, and displaying videos. Commercial support is also available, as well as enterprise features like distributed rendering, tracking, and live streaming.
Jaksta Music Miner for Mac automatically captures and tags MP3s from popular audio and video Web sites. Just open Jaksta Music Miner, play a song or video, and the MP3 is created, usually up to 10x faster than real time. The MP3 can be added to iTunes with the click of one button. It supports Grooveshark, Last.FM, YouTube, Jango, and more and is great for discovering new music or enjoying your music offline.
mixd.tv helps you discover videos from your favorite online sources. You can use text searches or browse channels, add your favorite videos to the video library or publish them to the mixd.tv community in a playlist or via Facebook, and subscribe to channels and receive automatic updates.
HeldenViewer makes it possible to search for, download, and view Youtube videos in a very easy to use fashion. An important feature is the concept of adding authors as favorites, in order to be notified at the next start of HeldenViewer if the author has uploaded a new video. You will no longer be interrupted by any commercials. Much like the Youtube platform, you can watch the videos while downloading and use your favorite videoplayer to do this. The only restriction is that the video player must be able to play .flv files, e.g. VideoLanClient.