require 'nztm2000'
  #Self test from nztm.c.
  nztm2000 = NZTM2000.new
  [[1576041.150, 6188574.240], 
   [1576542.010, 5515331.050],
   [1307103.220, 4826464.860]].each do |easting,northing|
     r_latitude, r_longitude = nztm2000.geod(easting, northing)
     r_easting, r_northing = nztm2000.nztm(r_latitude, r_longitude)
 
     printf "Input  NZTM easting, northing: %12.3f %12.3f\n", easting, northing
     printf "Output     Latitude Longitude: %12.6f %12.6f\n", r_latitude, r_longitude
     printf "Output NZTM easting, northing: %12.3f %12.3f\n", r_easting, r_northing
     printf "Difference:                    %12.3f %12.3f\n", easting - r_easting, northing - r_northing
     puts
  end

Land Information New Zealand (LINZ) does not offer any support for this software.
The software is provided "as is" and without warranty of any kind. In no event shall LINZ be liable for loss of any kind whatsoever with respect to the download, installation and use of the software.
The software is designed to work with MS Windows. However, LINZ makes no warranty regarding the performance or non-performance of the software on any particular system or system configuration.
 
Last Updated: 24 November 2014