This is a fork of Xdialog. From Xdialog homepage:
"Xdialog is designed to be a drop in replacement for the "dialog" or "cdialog" programs. It converts any terminal based program into a program with an X-windows interface. The dialogs are easier to see and use while adding even more functionalities (e.g. with the treeview, the file selector, the edit box, the range box, the help button/box). Because Xdialog uses GTK+, it will also match your desktop theme."
Xdialog is no longer actively development, hence this fork, to keep patches of Xdialog as used in Fatdog64. It was forked from the latest known version, 2.3.1.
The trunk branch now compiles for gtk2 (properly) and gtk3 (with lots of deprecation warnings).
If you need the original gtk1/gtk2 version, you can find it in the "gtk12" branch (which compiles for gtk2 with deprecation warnings, and supposedly compiles for gtk1 too - but it is __never__ tested and I don't even know if it still works).
Xdialog was first written by Alfred at Cyberone Internet, and later maintained by Thierry Godefroy from version 1.1.0 onwards (until the latest known version 2.3.1). It is licensed under GNU GPL Version 2.