Yad (short from Yet Another Dialog) is an open source fork of Zenity with many improvements.
It features custom buttons, additional dialogs, popup menu in notification icon and much more.
Product's homepage
Requirements:
· gtk+
What's New in This Release: [ read full changelog ]
· default value for combo-box can be specified by --entry-text from one of existings entries in list
· add --single-click option for icon dialog
· add log window to progress dialog
· fix geometry settings for unresizable windows
· fix layout on gtk3
· add custom signals for --kill-parent option