Connecting to Media Server

[Black Mage]

What programs can I use to connect to a media server in Linux, Mac and Windows?

And I mean programs that are similar to the PS3, where it connects to the server and then it searches for the media and then list the media found for the users to stream from the server to their computer.

[Acglaphotis]

I recommend Geexbox's uShare for this (you do not need Geexbox to use it, they offer a nice .deb package.)