NoMachine kept all original X.Org 6.9 files in the nx-X11 source
  tree. These files have been removed in Feb 2015 during a major
  code cleanup.

  For later studying we provide all diffs of the changes that
  NoMachine employed on the original X.Org X11 code tree in the
  doc/nx-X11_vs_XOrg69_patches folder.