Zenity is a free and open source cross-platform software library and set of tools used to create graphical user interfaces. It is written in C and released under the GNU Lesser General Public License. It can be used to develop both desktop and server-side applications and has been ported to all major platforms. Zenity provides users with a set of dialog boxes for common tasks, such as file selection, text input, and progress indication. It also allows for the creation of custom dialogs for more complex tasks. Additionally, Zenity can be used to create GUI scripts using the command-line interface, which can be used to automate system tasks. Zenity is a great tool for developers who want to create a GUI for their applications without having to learn a complex GUI framework.
In case you only need to display one message and do not want to need a large part of the gnome environment.
Discontinued The project is no longer being developed. The latest version, 7.4.2, released in June 2012, can still be downloaded from the official website.
Provides most of the same features as Zenity for Mac users.