Also DLLs, all of the Debian ecosystem, etc etc. So much incredible stuff (and DLLs too) that still exists, and powers most of what we build now.

Born in 84. I have been a user of all the above. The reason I mentioned GitHub to this level is truly in 2009 onwards it unlocked sharing of code at a level I had not seen before. It really did eclipse the reuse of software to what came prior and a lot of that has to do with the associated social network and network affects. They in a way game-ified software for a new generation. And it's not that we didn't share software before, just not to this degree and that's because every decade we rebuild the same ideas for a new generation that then 10-100x what came before. So something will come after GitHub as well. But today that's what we have and that really changed software for a generation.

I think Stack Overflow achieved the gamification and sharing of ideas much more than Github, and package managers such as NPM unlocked more and more reuse. Github has had some big benefits, but I think you're exaggerating quite a bit. Mercurial, SourceForge, etc etc were already around doing quite a lot of what early Github did, and while it's true that lots of projects transitioned from them to Github (it looked nicer, it was free and it was Git), it wasn't the sea change that some of the other platforms have brought.

To me it sounds like you mean GitHub put collaboration on a new level.

But reuse - no. I don't remember ever pulling a dependency from GitHub (stupid question, but is that even possible?), although I've been doing that for many years from Maven, NuGet, npm, CPAN.

Pulling dependencies from GitHub is standard usage for the package managers of Ruby, Go, Rust, and others. That is, they pull from Git, and it doesn’t have to be GitHub but it usually is.

Cargo does not pull from git or GitHub by default, you must specifically request that.

Sorry, yes, for Ruby and Rust I should have said “they can pull from git”. Point being, it is possible and when you do it GitHub is the most likely source.

Ruby gems (libraries) aren't pulled feom github. Yes, you CAN pull it from there, but most public and published gems don't come from there.

Don't you think immense availability is also detrimental ? crowdsourced ideas can lead to is_even.js too. I have a lot less appreciation for the recent years than most it seems.

I mean opinions are better than generic solutions so yea I think having X implementations of the same thing isn't of value but at the same time something as simple as github star count, forks, etc created a signal for what had momentum, impact and most use. Nothing is perfect but we find ways to overcome those issues. In reality we never end up with just one defacto standard but maybe ecosystems are born that end up being quite valuable.

I don't know, I see a lot of energy spent that's for sure but a lot of running in circles too. I miss centralization a bit (just a bit)