*.tar.gz are gzipped tar files.  ftp them using binary mode, run
gunzip on them and then extract the individual files with tar.

userlib.tar.gz contains a set of IDL *.pro files which NASA Goddard Code 916
	has found useful.
idldata.tar.gz contains a set of data files (mainly color tables and the 
	continental outlines data file) for use with routines in
	userlib.tar.gz

To install, you will want to do something like this:
   mkdir -p $IDLDIR/local/userlib
   cd $IDLDIR/local/userlib
   gunzip -c userlib.tar.gz | tar -xovf -
   mkdir $IDLDIR/local/data
   cd $IDLDIR/local/data
   gunzip -c idldata.tar.gz | tar -xovf -

where $IDLDIR is the directory in which IDL is installed on your
system. This is usually either /usr/local/rsi/idl/, or /opt/rsi/idl/.

To use these routines, you must alter your user environment 
variable:
   add "+$IDLDIR/local/userlib" to your IDL_PATH
   define IDLDAT as "$IDLDIR/local/data/"
   define IDLCOL as "$IDLDIR/local/data/colors/"


**** WARNING !!! WARNING !!! WARNING !!!! ****   

When you have unpacked the library routines, you will find
a directory $IDLDIR/local/userlib/dup/.  In this directory
are routines that have the same names as routines that come
with IDL, but which are **NOT** compatible with the IDL versions.
There are unfortunate historical reasons why this is so, but
be aware that you might very well want to:
  - remove this directory of dups
  - remove it from the $IDL_PATH
or 
  - put these routines at the *end* of the $IDL_PATH, so that the 
    IDL versions are found first.