GD::Graph is excellent, and there's also Gnuplot. They both have lots of different types of graphs and styling options.

Though not a Perl solution, I recently started using the really cool FusionCharts, which is a Flash widget that downloads data from your server (in XML) and renders really cool looking graphs client-side.

Though not a Perl solution, I recently started using the really cool FusionCharts, which is a Flash widget that downloads data from your server (in XML) and renders really cool looking graphs client-side.

There's XML/SWF Charts too, and it has a Perl interface!

--
David Serrano

Update: Sorry, I did not read your question with enough attention. GD::Graph is not based on simple text input for the graphics definition.

The work is not entirely in your hands, and you obviously need "the internets", and it's not Perl. On the otherhand it's flexible, simple, and powerful.

You just send the appropriate URL and get back a PNG image of your graph/chart/map/whatever.

The previous posters gave excellent input. Allow me to expand and enhance. I recently put quite a bit of time into understanding gnuplot. Be warned that the options available to you in a graphics window are different than those that are available when you print to a file. This, and the non-orthogonal arrangement of options, caused my quite a lot of consternation. I eventually decided gnuplot did not suit my data set so I ended up switching back to GD and it's offspring. Now I'm much happier.

I case you wind up going that route, here is a perl script to launch gnuplot and feed it a list of commands. The commands generate a png file.

#!/usr/bin/perl
#
# ptoplot.pl
#

use strict;
use warnings;

my $output_file = "graphics/plot1";
my $cmd = '| gnuplot - 2>&1';
open PLOT, "$cmd" or die;

while (<DATA>) {
    print PLOT "$_";
}

qx("sync");

__DATA__
set terminal png medium color picsize 800 600
set output "graphics/plot1"
set title 'Splot of file plot.dat'
set style data dots
# set hidden3d
# set data palette
set contour base
set zlabel 'amplitude'
splot  "graphics/plot.dat" matrix with lines

show output
[download]

The amazing program gnuplot has already been mentioned, but it's worth repeating. An alternative is grace, which is also a plotting utility that takes a plain text file as input. It also comes with xmgrace, a front end that generates these files.