It is network link from the TV/Device to a media server

The home page

Some servers for different OS-es

another list

How to build media PC: http://www.linuxjournal.com/article/10111

Comprehensive list of known DLNA-Compliant and UPnP media server applications

Mac OSX

• Allegro Media Server
• Cidero Internet Radio Station Server
• Cyber Media Gate
• Elgato Eyeconnect
• Rhapsody
• TwonkyMedia

Windows

• Allegro Media Server
• Cidero Internet Radio Station Server
• Cyber Media Gate
• Cyberlink Digital Home Enabler Kit
• Fuppes
• Musicmatch Jukebox
• Nero MediaHome
• On2Share
• Rhapsody
• SimpleCenter
• TVersity (free)
• TwonkyMedia
• Windows Media Connect (free)

Linux

• Cidero Internet Radio Station Server
• Cyber Media Gate
• Fuppes
• Geexbox -Multimedia pc LIVE CD
• GMediaServer
• MediaTomb
• MythTV
• TwonkyMedia
• uShare

taken from this xbox tutorial

Multimedia Centers

Linux Multimedia Center – http://app.boxee.tv/download

TV Streaming website – http://www.hulu.com/

USB XBOX MMCenter http://lifehacker.com/395212/run-xbox-media-center-from-a-usb-drive

Nice Podcasts viewer – http://www.getmiro.com/download/