GTK - GTK+ is a multi-platform toolkit for creating graphical user interfaces.
Microsoft Visual Studio - Microsoft Visual Studio is an integrated development environment (IDE) from Microsoft.
PyQt - Riverbank | Software | PyQt | What is PyQt?
Visual Studio Code - Build and debug modern web and cloud applications, by Microsoft
wxWidgets - wxWidgets: Cross-Platform GUI Library
Xcode - Xcode is Apple’s powerful integrated development environment for creating great apps for Mac, iPhone, and iPad. Xcode 4 includes the Xcode IDE, instruments, iOS Simulator, and the latest Mac OS X and iOS SDKs.