#!/usr/local/bin/perl -w
#
# Simple Tk script to create a button that prints "Hello, world".  Cli
+ck on
# the button to terminate the program.
#
# The first line below imports the Tk objects into the application, th
+e second
# line creates the main window, the third through sixth lines create t
+he button
# and defines the code to execute when the button is pressed, the seve
+nth line
# asks the packer to shrink-wrap the application's main window around 
+the
# button, and the eight line starts the event loop.

use Tk;
$MW = MainWindow->new;
$hello = $MW->Button(
    -text    => 'Hello, world',
    -command => sub {print STDOUT "Hello, world\n"; exit;},
);
$hello->pack;
MainLoop;
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I just changed the sentence to an Arabic one

...but that's the interesting part :)

In other words, the very way of specifying the Arabic text may be the reason it's not working.  For example, did you specify UTF-8 characters literally in the code (using a UTF-8 capable editor — in which case you'd need "use utf8;")?  Or did you use \x{....} escapes?  Did you use Unicode at all or some legacy encoding/code page?  Etc...

Thank you sir, I don't know if it is now fully supported but I do have Arabic support for now,.. Thanks for your help