Qt
Open Source
Qt (cute) is a cross-platform application framework that is used for developing application software that can be run on various software and hardware.
PyQt
Open Source
PyQt is a Python binding of the cross-platform GUI toolkit Qt, implemented as a Python plug-in.
wxPython
Open Source
wxPython is a wrapper for the cross-platform GUI API.
Electron / Atom Shell
Open Source
Electron helps you build cross platform desktop apps with JavaScript, HTML, and CSS.
wxWidgets
Open Source
wxWidgets (wix-widgets, formerly wxWindows) is a widget toolkit and tools library for creating graphical user interfaces (GUIs) for cross-platform application…
wxSVG
Open Source
wxSVG is C++ library to create, manipulate and render Scalable Vector Graphics (SVG) files with the wxWidgets toolkit.
Compare GTK+ with alternatives
Compare Electron / Atom Shell and GTK+ and decide which is most suitable for you.