It’s for storing your DSs, obviously.

Kind of a mac’s version of desktop.ini. Remembers layouts and other metadata about a folder.

I learned of those files outside the context of programming. When program or file zip packages contained these random ds store files and I looked up what they are.

Turns out, it’s metadata caching for macOS. Irrelevant and does not belong into [distributed or shared] packages.

/edit: It’s been a long time ago. Looking at it again, I guess it adds folder metadata, so it could be useful when distributing to other macOS. But for other OS, it’s noise. Either way, usually it’s not intentionally included.