Glade has been discontinued. Similar apps include Qt Creator, which is open source but paid. Cambalache and Anjuta are free. Other options are GNOME Workbench, Yad, wxFormBuilder and wxDev-C++. You can choose from more than 10 Shells like Glade for Linux, Windows and Mac.
Qt Creator is a cross-platform integrated development environment (IDE) built for the maximum developer experience. Qt Creator runs on Windows, Linux, and macOS desktop operating systems and allows developers to create software across desktop, mobile, and embedded platforms.
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Cambalache is a new RAD tool that allow development of user interfaces for Gtk 4 and Gtk 3 toolkit. It was born as a substitute for Glade.
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Anjuta is a versatile Integrated Development Environment (IDE) for C and C++ on GNU/Linux. It has been written for GTK/GNOME and features a number of advanced programming facilities including project management, application wizards, an interactive debugger and a powerful source...
Workbench lets you experiment with GNOME technologies, no matter if tinkering for the first time or building and testing a GTK user interface.
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Yad (yet another dialog) is a fork of Zenity with many improvements, such as custom buttons, additional dialogs, pop-up menu in notification icon and more. It's useful for creating quick and easy GUIs for shell and batch scripting.
wxWidgets is an excellent framework that enables the creation of multi-platform applications with and without a graphical user interface. There are several applications that help create dialogs visually, even so, some practical problems have led me to start the development of a...
wxDev-C++ is an extension of Bloodshed Dev-C++ by Colin Laplace et. al. This program helps you to create dialogs and frames for wxWidgets visually using a form designer.
kdialog allows you to display dialog boxes from shell scripts. The syntax is very much inspired from the "dialog" command (which shows text mode dialogs).
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wxGlade is a GUI designer written in Python with the popular GUI toolkit wxPython, that helps you create wxWidgets/wxPython user interfaces. At the moment it can generate Python, C++, Perl, Lisp and XRC (wxWidgets' XML resources) code.
