gui-toolkit

A cross-platform Software Development Kit including a GUI toolkit, a 2D/3D graphics engine, a networking library, an audio output library, an IDE, a compiler for the eC programming language, and more.

GTK is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK is suitable for projects ranging from small one-off tools to complete application suites.

pywebview is a lightweight cross-platform wrapper around a webview component that allows to display HTML content in its own native GUI window. You may think of as Electron for Python (minus huge executable sizes).