To install Essence, you'll need to compile and install the Essence
source code and its related programs, then apply some patches to the
WAIS source code, and compile and install a subset of the WAIS
programs.  Read the README file and the Essence manual page for
information on how to use Essence once you've installed it.

Follow these steps to install Essence:

0) Unpack the Essence distribution.

      csh% zcat Essence-1.1.tar.Z | tar xvf -

1) Choose an installation directory.

   Choose a directory in which all of the Essence summarizers and
   executables will be installed.  Edit 'Makefile', and set INSTALLDIR
   to this directory.  Also set MANDIR to the directory in which you
   want the Essence manual pages installed.  

   NOTE: You may want to choose an empty directory since Essence will 
         install a few dozen programs into INSTALLDIR.

2) Retrieve the WAIS distribution (version 8-b5.1) and unpack into Essence's 
   'src' directory.  Once you've unpacked the WAIS distribution, set the 
   'TOP' variable in WAIS's top-level makefile (wais-8-b5.1/Makefile).


   NOTE: The distribution is available via anonymous ftp from 
         ftp.think.com in /wais.  You can retrieve a more recent 
         version of WAIS, if one is available.

      csh% cd src

      csh% ftp ftp.think.com
      Connected to Think.COM.
      220 early-bird.think.com FTP server (SunOS 4.1) ready.
      Name (think.com:hardy): [* TYPE anonymous *]
      331 Guest login ok, send ident as password.
      Password: [* TYPE YOUR EMAIL ADDRESS *]
      230 Guest login ok, access restrictions apply.
      ftp> cd /wais
      ftp> dir wais-8-b5.1.tar.Z
      200 PORT command successful.
      150 ASCII data connection for /bin/ls (128.138.243.152,1381) (0 bytes).
      -rw-rw-r--  1 1556     staff      775527 Nov 16  1992 wais-8-b5.1.tar.Z
      226 ASCII Transfer complete.
      remote: wais-8-b5.1.tar.Z
      73 bytes received in 0.45 seconds (0.16 Kbytes/s)
      ftp> binary
      ftp> get wais-8-b5.1.tar.Z
      ftp> bye
      csh% zcat wais-8-b5.1.tar.Z | tar xvf -
      csh% rm -f wais-8-b5.1.tar.Z


3) Apply the Essence patches to WAIS's 'ir' source directory.

      csh% cd src/wais-8-b5.1/ir
      csh% patch < ../../Essence-WAIS.patch

   Verify that all of the patches succeeded.  If you retrieved a more
   current version of WAIS than 8-b5.1, the patches may no longer work.
   These patches will not work with the freeWAIS distribution.

   NOTE: The src/Essence-freeWAIS.patch file is based on freeWAIS-0.202;
         it's untested, but it should work.  See doc/FAQ.txt for more
         information.  We appreciate any comments/feedback on using 
         Essence with freeWAIS.
         

4) Verify that you have the appropriate supporting software installed
   (run 'make verify'), and then setup Essence configuration files.

   Essence uses a number of public-domain software packages to accomplish
   semantic indexing.  To effectively use Essence's semantic indexing
   facilities, you will need to configure Essence to your local site's
   semantics.

   First, run 'make verify' to verify that Essence's summarizers have all
   of the necessary external programs to run, and to verify that you have
   Perl 4.0 installed as Essence assumes.  Install any programs that it
   cannot find, or remove the questionable summarizers from the summarizer
   directory (src/essence/summarizers).

   NOTE:  'make verify' uses your environment variable $PATH to search for
          programs.  Please make sure that your $PATH variable is set
          appropriately before running 'make verify'.

   Second, if you want, modify the .cf files (in src/essence) to change
   the rules for how Essence determines file types.  You may also want
   to change default stoplist (src/essence/stoplist); Essence will not
   index or summarize any files that match one of the file types
   specified in the stoplist file.  Read the Essence manual page for
   more information on the .cf files.

5) Build the source; type 'make' from the top-level Essence directory.

   NOTE:  Compiling WAIS may generate warnings which can be ignored.

6) Install Essence; type 'make install' from the top-level Essence directory.

   'make install' will install everything into INSTALLDIR and the manual 
   pages into MANDIR.

7) Put INSTALLDIR first in your path before you run 'essence'.

   For example, if you choose INSTALLDIR to be /usr/local/essence/bin,
   then type

      csh% set path = (/usr/local/essence/bin $path)

8) Read the manual page for Essence.


Have Fun.  Please send comments/bugs to hardy@cs.colorado.edu (Darren Hardy) 
and/or schwartz@cs.colorado.edu (Mike Schwartz).
