git
the wonderful tool nobody uses

except some programmers and aficionados, of course.
git is huge. it’s the name of the currently most used versioning tool. a version control system, or vcs for short. “git” is by far the biggest tool under what we could call “vcs 2.0” (so i’ll just both terms interchangeably).
versioning is basically the right way to do digital [backup] of files. instead of creating new files with different names (“final dream manifesto 03.doc” means anything to you?), we create different versions of the same file (so it can be called just dream.doc). without this, [wikipedia] would not exist.
doing vcs with git adds inconceivable benefits to the untrained in the same category of versioning tools (hg is another example). it’s like trying to make ice cream with a knife, rather than a blender. or building a sand castle with a kid’s shovel, rather than a 3d printer.
at least 99% of the digital world today would not exist without vcs. huge [catalyst]. how much of that we can attribute to git is a big question and probably the reason why there’s no vcs 3.0 in so long. still, it could as well be all of it. because for sure git is a catalyst.
github
it was the first central hub for git. and where this site is hosted, for free. bought by microsoft in 2020, it started its downward spiral into oblivion.
gitlab
it’s the [foss] version of github. truly remarkable! and next home for this site.