What was once old is new again and the desktop-centric computing is making way for return of thin client/mainframe computing again. This tutorial will walk you through setting up a Ubuntu desktop to act as a "mainframe", capable of being accessed by a thin clients or regular desktops, using the excellent FreeNX server.

FreeNX is an open source implementation of NoMachine's NX Server. It is a bit more akin to Microsoft's RDP protocol that the usual VNC, so while keeping bandwidth to a minimum, it maintains good visual quality and responsiveness. You can connect using NoMachine's monetarily free NX Client, which is available for Windows, OS X, Linux or Solaris. Also, by default, all traffic is via SSH, so your connections are encrypted.

Via HowToForge.com