This package is prerex-4.1. It consists of 

  README                this file 
  prerex.sty            a LaTeX document style for prerequisite charts 
  src/prerex.c 
  src/inout.c 
  src/edit.c
  src/prerex.h          sources of a C program for editing prerequisite charts 
  src/Makefile          supports make prerex
  src/kpdf-3.5.8.patch  patch to create prerex-enabled kpdf from kdegraphics-3.5.8
  src/kpdf-3.5.9.patch  patch to create prerex-enabled kpdf from kdegraphics-3.5.9
  src/okular-4.0.3.patch  patch to create prerex-enabled okular from kdegraphics-4.0.3
  src/COPYING           GPL 
  doc/intro.pdf         introduction to the prerex system
  doc/prerex.1          man page for prerex 
  doc/prerex.sty.7      man page for prerex.sty 
  doc/prerex.5          man page defining the format acceptable to prerex(1) 
  doc/prerex.{tex,pdf}  expanded version of prerex.sty.7 
  chart.{tex,pdf}       example chart 
  Makefile              supports make file.pdf for a file.tex using prerex.sty

See the file doc/intro.pdf for an overview of the prerex system.

prerex.sty depends on

  pgf (and add-on tikz), version 1.10 or higher 
  multido
  relsize
  calc
  ifthen
  color
  hyperref

The use of pgf means that Postscript processing is not required;
either pdflatex or latex -> dvips [ -> ps2pdf ] may be used.

The Optima type face is recommended for prerequisite charts. Authentic
Linotype Optima fonts (or the Bitstream Zapf Humanist 601 clones) may be
purchased commercially; support files are available here:

  fonts/psfonts/w-a-schmidt/pop.zip
  fonts/psfonts/w-a-schmidt/bop.zip

The URW Classico fonts available at

  fonts/urw/classico

are acceptable "free" alternatives.

Futura and Gill Sans also work well in prerequisite charts.

The prerex editor depends on the GNU readline and history libraries.
I have used it only on Linux and on Solaris, but it should build and
run on any system that has an ANSI C compiler and the GNU libraries,
including the Cygwin platform on Windows and the Fink platform on Mac OS X.

kpdf (now part of okular) is a GPL-ed PDF viewer for KDE. The
kpdf/okular patch files can be used to build a "prerex-enabled" version
with the following additional features:

1. The URI of any hyperlink is displayed in a "tooltip" if the mouse
   hovers over the hyperlink. (The Adobe Reader has the same feature.) In
   particular, if the PDF being viewed is a prerex-formatted chart (with
   the coordinate grid enabled), hovering the mouse over a course box
   or mini will display a URI of the form coord: x,y, where x,y are the
   coordinates of the (centre of) the course box; similarly, hovering
   the mouse over the mid-point of an arrow will display the coordinates
   of its source and target boxes.

2. If the PDF being viewed is a prerex-formatted chart (with the
   coordinate grid enabled), clicking in a course box/mini or arrow will
   put the coordinates of the box/mini centre or of the arrow source
   and target boxes into the X clipboard; the coordinates can then
   be "pasted" into a command being composed at the prerex prompt by
   middle-clicking the mouse. Similarly, clicking on any point in the
   background coordinate grid will put the coordinates of that point
   into the X clipboard. The "hand" or "arrow" cursor changes to a
   "crosshair" cursor to signal successful capture of coordinate values
   (until the mouse moves).

Installation of prerex.sty:

  + copy prerex.sty to your-texmf-tree/tex/latex/misc
  + copy doc/prerex.{tex,pdf} to your-texmf-tree/doc/latex/misc
  + if necessary, refresh the TeX database (e.g., texhash)
  + copy doc/prerex.sty.7 to sub-directory man7 of a man directory on your 
    MANPATH
  + test by doing 

       man 7 prerex.sty
       make chart.pdf

Installation of prerex:

  + cd src
  + make prerex
  + copy prerex to any directory on your PATH 
  + copy doc/prerex.1 and doc/prerex.5 to sub-directories man1 and man5 of a 
    man directory on your MANPATH
  + test by doing 

       man 1 prerex
       man 5 prerex
       prerex chart

Installation of prerex-enabled kpdf/okular:

kpdf/okular is distributed as part of the kdegraphics package. Install
kdegraphics-x.y.z (and the KDE libraries it depends on), where x.y.z
is the version number in the name of the patch file. Also obtain the
sources for the relevant version of kdegraphics, either directly from

ftp://ftp.kde.org/pub/kde/stable/

or using the source package for a distribution. Unpack the source and
apply any distributor-supplied patches.

Move to the kdegraphics-x.y.z directory and do

 cp -r kpdf kpdf.orig

or

 cp -r okular okular.orig

Copy the patch file to the kdegraphics directory and do

 patch -p0 < patch-file 

If the patch is successful, do

 ./configure --prefix=/usr

for kde-3 or 

 cmake -D CMAKE_INSTALL_PREFIX:PATH=/usr .

for kde-4. If the configuration step is successful, move to the
(patched) kpdf/okular directory and do

 make 
 make install  (as root)

You do not have to build and re-install all parts of kdegraphics;
the "make" and "make install" will build and over-write just the
kpdf/okular-related portions.

When you start up kpdf/okular, verify that "This is prerex-enabled
kpdf [okular]" is displayed in the statusbar and that the additional
features work as advertised.

prerex.sty, README.prerex, prerex.1, prerex.5, prerex.sty.7, prerex.tex
and chart.tex may be modified and distributed according to the terms of
the LaTeX Project Public License.

The source files for prerex and the kpdf/okular patches may be modified
and distributed according to the terms of the GNU General Public Licence
(version 2).