There are 2 repositories under gog-games topic.
An Itch.io/Epic Games/GOG launcher that works through plugins
Launch GOG games with GOG Galaxy using shortcuts and add shortcuts for GOG games into Steam Library
A tool created to read, write and modify scripts of the 1999 rpg game 'Silver'.
Flow launcher plugin for searching and launching games from multiple platforms like Steam, Epic Games, Xbox etc.
Create start menu tiles of your favorite games in Windows 10
GOG.com games catalog browser | Flask, GOG API, Bootstrap
GoG-WebApiKit is an unofficial .NET Core library with the purpose, to simply interact with the GoG API.