GNOME Builder is fast, clean & simple IDE for GTK application development (on Linux), integrated support for Git and easy possibility to publish the application on FlatHub. This is probably the best IDE for developing applications on Linux
Yad - Yad (yet another dialog) is a fork of Zenity with many improvements, such as custom buttons...
Geany - Lightweight IDE for Linux and Windows
Glade - Glade is a RAD tool to enable quick & easy development of user interfaces for the GTK+ toolkit...
Visual Studio Code - Build and debug modern web and cloud applications, by Microsoft
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.