This is GRG 3.2 distributive.  It contains the following files:

  README          - the file you are reading now
  grg32r6.zip     - DOS distributive
  grg32r6.tar.gz  - UNIX distributive

To install GRG 3.2 you have to unpack the distributive.
For DOS:      unzip grg32r6.zip
For UNIX:     gzip -d grg32r6.tar.gz
              tar -xvf grg32r6.tar

Read the file readme.txt and follow the instruction contained therein.

Notice that DOS and UNIX distributives are identical.
They differ only by text files encoding. DOS distributive contains
little programs which converts DOS text files into UNIX format and back.