NX and FreeNX server are only available for CentOS-4 and CentOS-5 i386
NX is a Terminal Server and Remote Access solution based on a comprising set of enterprise class open source technologies by NoMachine. Thanks to the outstanding compression, session resilience and resource management developed on top of the X-Window system, and the integration with the powerful audio, printing and resource sharing capabilities of the Unix world, NX makes it possible to run any graphical application on any operating system across any network connection as if you were sitting in front of your CentOS computer.
When making a connection, you have the server computer (the computer you will connect to and open the desktop from) and the client computer (the computer you are using to make the connection to the server).