I absolutely love their client and prefer GOG over Steam. I remember how their client GOG Galaxy is highly praised in the developer community, because it is so well designed and runs so performant. It also allows you to play any previous versions of games you own.
https://www.reddit.com/r/gog/comments/fhd6b1/what_was_gog_galaxy_20_made_with/
https://en.m.wikipedia.org/wiki/Splitting_of_the_Moon