Its hard to test Tk against C, but with Gtk2 it can be done. Below are the same program, one in Gtk2-c and one Gtk2-perl. Here are the top output when run:

# for c version
zentara   15   0 14368    7012   5400   S    0.0    0.7    0:00  .07 .
+/basic-window-c 

#for the Perl version
zentara   18   0   21700  12m    9056    S   0.0   1.3    0:00     12 
+ 
./basic-window.pl
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As you can see Perl uses way more memory; 12m versus 7k for c. The question becomes, with systems with 1 and 2 gigs of ram being common, can you afford the extra ram usage, in exchange for the ease of writing it in Perl? For me, the answer is yes. C can take hours, where Perl is done in minutes.

/* compile  test-c.c with 
gcc  -o test-c  test-c.c  `pkg-config --cflags --libs gtk+-2.0`
*/

#include <gtk/gtk.h>

void destroy(GtkWidget *widget, gpointer data)
{
        gtk_main_quit();
}

int main(int argc, char *argv[])
{
        GtkWidget *window;
        GtkWidget *button;
        gtk_init(&argc, &argv);
        window = gtk_window_new(GTK_WINDOW_TOPLEVEL);

        g_signal_connect (G_OBJECT (window), "destroy", G_CALLBACK(des
+troy), 1);

        gtk_container_set_border_width(GTK_CONTAINER (window), 10);
        button = gtk_button_new_with_label ("Some Button");
        gtk_container_add(GTK_CONTAINER(window), button);
        gtk_widget_show(button);
        gtk_widget_show (window);
        gtk_main ();
        return 0; 
}
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#!/usr/bin/perl
use warnings;
use strict;
use Gtk2 '-init';

my $window = Gtk2::Window->new;
my $button = Gtk2::Button->new('Some Button');
my $vbox   = Gtk2::VBox->new();
$window->set( border_width => 15 );
$window->add($button);

$window->signal_connect('destroy', sub { Gtk2->main_quit });

$window->show_all();

Gtk2->main;
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