PAR-WebStart helper applications

Beneath the par/ subdirectory are files enabling one to
provide support of installation of CPAN distributions and
Win32 ppm packages via a PAR::WebStart application. 
PAR-WebStart is a helper application associated
with a browser. When a user clicks on a link that points to a 
PNLP [PAR Network Launch Protocol] launch file (a special XML file), 
it causes the browser to launch PAR-WebStart, which then 
automatically downloads, caches, and runs the specified
PAR-based application. 

To enable this feature, first install the PAR-WebStart distribution
from CPAN. The PAR applications may then be built with the
make_par.pl script of PAR-WebStart:

  $ cd par
  $ cd cpan
  $ make_par.pl --name cpan --dst_dir /path/to/Apache/htdocs/par_directory
  $ cd ../ppm
  $ make_par.pl --name ppm --dst_dir /path/to/Apache/htdocs/par_directory

This will produce PAR applications signed with Module::Signature;
if you want to disable such signing, pass the "--no-sign" option
to the make_par.pl script.

Links to launch these applications are enabled through the "mirror"
menu item of CPAN-Search-Lite web pages by checking the indicated
checkbox. The links point to the "cpaninstall" and "ppminstall"
locations specified within tt2/config, and are intended to be
handled by the Apache2::WebStart handler of PAR-WebStart (this creates
the PNLP xml file used by the client to launch the application). 
Example Apache directives are

 PerlModule Apache2::WebStart
 <Location /cpan_install>
   SetHandler perl-script
   PerlResponseHandler Apache2::WebStart
   PerlSetVar WS_codebase "par_directory"
   PerlSetVar WS_title "CPAN install"
   PerlSetVar WS_vendor "Your institution name"
   PerlSetVar WS_homepage "docs/webstart.html"
   PerlSetVar WS_description "Install CPAN modules via PAR::WebStart"
   PerlAddVar WS_par "cpan.par"
   PerlSetVar WS_long_opts 1
 </Location>
 <Location /ppm_install>
   SetHandler perl-script
   PerlResponseHandler Apache2::WebStart
   PerlSetVar WS_codebase "par_directory"
   PerlSetVar WS_title "PPM install"
   PerlSetVar WS_vendor "Your institution name"
   PerlSetVar WS_homepage "docs/webstart.html"
   PerlSetVar WS_description "Install Win32 ppm packages via PAR::WebStart"
   PerlSetVar WS_os "MSWin32"
   PerlAddVar WS_par "ppm.par"
   PerlSetVar WS_long_opts 1
 </Location>

If you disabled signing of the PAR applications by Module::Signature
when making the applications by make_par.pl, add the directive

   PerlSetVar WS_no_sign 1

within these locations. The above directives will specify the
par files to be accessible under

  http://your.server.edu/par_directory/

with a help page (available under the htdocs/ subdirectory) found as

  http://your.server.edu/docs/webstart.html
