[FreeNX-kNX] Attaching to a running X desktop, and FreeNX installation instructions

[JCA]

  Is it possible, using either FreeNX or the NX server from NoMachine,
to remotely attach to a currently running ordinary X desktop?

  Another issue: Is there a document where the installation procedure
for FreeNX is presented in gory detail? The material in the tarballs
is confusing, and the compilation of the NX sources, baffling: I have
yet to be able to build the nx-X11 component, and it is not clear what
components must be built, and in what order.

   Other than that, this looks like a terrific technology, which I am
looking forward to using.