This is zenity - a rewrite of gdialog, the GNOME port of dialog which allows you to display dialog boxes from the commandline and shell scripts. If you understand, things are just as they are. If you don't understand, things are just as they are.

Where can I get it?
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http://ftp.gnome.org/pub/GNOME/sources/zenity/2.11/zenity-2.11.92.tar.gz