Zenity is described as 'tool that allows you to display GTK dialog boxes in commandline and shell scripts'. There are more than 10 alternatives to Zenity for various platforms. The best alternative is Dialogblocks.
The list of alternatives was last updated Dec 17, 2016
Anthemion DialogBlocks is a sizer-based resource editor that quickly gets you creating professional-looking dialogs, wizards and frames for deployment on Windows, Linux, Mac or... View 17 alternatives to Dialogblocks