Zenity - Zenity is a tool that allows you to display GTK dialog boxes in commandline and shell scripts.
Dialogblocks - DialogBlocks is a cross-platform wxWidgets dialog editor for Windows, Unix and Mac.
Yad - Yad (yet another dialog) is a fork of Zenity with many improvements, such as custom buttons...
wxFormBuilder - wxWidgets is an excellent framework that enables the creation of multi-platform applications with...
dialog - Dialog is a handy and feature-rich enterprise multi-device messenger available for server or cloud.
Glade - Glade is a RAD tool to enable quick & easy development of user interfaces for the GTK+ toolkit...