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
Geany - Lightweight IDE for Linux and Windows
Notepad++ - A free source code editor which supports several programming languages running under the MS Windows environment.
Visual Studio Code - Build and debug modern web and cloud applications, by Microsoft
Notepad3 - Notepad3 is a fast and light-weight Scintilla-based text editor with syntax highlighting.
Glade - Glade is a RAD tool to enable quick & easy development of user interfaces for the GTK+ toolkit...
TED Notepad - TED Notepad is a portable text editor software that deals with a large variety of text processing tools, supplemental text clipboards, high accessibility through hotkeys, and a customizable number of settings and options.