What is DLNA3????????????

It's a standard used to stream media over a network. If a software or hardware uses this standard to stream media you can use it to view movies/music/pictures on the PS3.

http://en.wikipedia.org/wiki/Digital_Living_Network_Alliance

http://www.twonkyvision.com/Products/TwonkyMedia/index.html 

You can also use Windows Media Connect or Windows Media Center to stream stuff to your PS3 as both of them support DLNA.