[adastra22]

Git is not a protocol, it is a data format. That only makes sense when your VCS system is similar enough to git to easily allow converting between the two representations.

[simonw]

I mean things like git-svn, hg-git, git-p4, git-remote-fossil, git-tfs, jj.

[adastra22]

Every single one of those is following variations on the exact same data structure, or is actually git in a trenchcoat.