Movgrab is a command-line movie downloader for sites like YouTube. It has no dependencies; everything that's needed should be there in the tar.gz package. Movgrab can connect through an HTTP proxy, can output the download to stdout for piping into another program, and can fork into the background to free up the console. When forked into the background, its progress can still be seen in a ps list.
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.
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.
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.
eduMagnet can search and access different online video sites (YouTube, Blip, TeacherTube, RSS, German public TV, etc). Students and pupils can create playlists of lectures and talks and play educational content using an embedded video player (MPlayer). As an OLPC project eduMagnet is developed for the sugar OS, but can also be used in any Linux environment using GTK. Students may synchronize playlists to the online platform eduMagnet.org so that other users can subscribe to their playlists. Access to new online video sites can easily be added using python plugins ("Magnets").
Elmedia Player PRO makes it easy to download videos from online sources such as YouTube, Vimeo, DailyMotion, Metacafe, and many others. Using it is just a matter of entering the link to the page with your desired video in Elmedia Player and choosing the content you want to download from the list. When you are downloading SWF files, you are given the option to preview all external resources used by the SWF animation. You can download them along with the SWF file if you wish, or even download just the external resources without the initial SWF. Other features include full-screen mode, "Always on top" mode, the ability to make screenshots of your favorite movie moments, and the ability to convert the whole movie into a series of images.
FatRat is a download manager that is rich in features and is continuously extended. Its features include HTTP(S)/FTP/SFTP downloads, FTP/SFTP uploads, RSS feed support with special functions for TV shows and podcasts, BitTorrent support (including torrent creation, DHT, UPnP, and encryption), torrent searching, Support for SOCKS5 and HTTP proxies, RapidShare.com FREE downloads, RapidShare.com uploads, RapidShare.com link verification and folder extraction, RapidSafe link decoding, MD4/MD5/SHA1 hash computing, remote control via Jabber or a Web interface, and YouTube video downloading.