Tk

The main goal of the Tk system is to simplify the construction of graphical user interfaces (GUIs). It works in combination with a scripting language such as Tcl or Perl, and provides a collection of "widgets", which are essentially parameterized building blocks of GUIs, such as drop down menus, buttons, and input boxes.

Tk is an interpreted language, that is, a Tk program is not pre-compiled when executed. It is available on all major operating system platforms, including Linux, Mac OS, and Windows.

Most Tk widgets are actually abstract concepts that require specification of parameters to determine the appearance and functionality of a particular widget instantiation. For example, the width, height, and color of a widget typically needs to be specified, or the number of elements in a menu.

You can find all the available widgets and parameters in the Tk documentation.