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
Brackets - A modern, open source text editor that understands web design
Geany - Lightweight IDE for Linux and Windows
Atom - At GitHub, we’re building the text editor we’ve always wanted: hackable to the core, but approachable on the first day without ever touching a config file. We can’t wait to see what you build with it.
Visual Studio Code - Build and debug modern web and cloud applications, by Microsoft
Sublime Text - Sublime Text is a sophisticated text editor for code, html and prose - any kind of text file. You'll love the slick user interface and extraordinary features. Fully customizable with macros, and syntax highlighting for most major languages.
Glade - Glade is a RAD tool to enable quick & easy development of user interfaces for the GTK+ toolkit...