[mikepurvis]

Almost any project you work on will have an authoritative copy of the repo in some kind of web-accessible tool, most of which provide a tarball-download function.

And GitHub's scheme is pretty much a de-facto standard at this point—GitLab's implementation is an exact copy of it, for example:

    https://<host>/<org/project>/archive/<ref/branch/tag>.tar.gz

Edit to add: Also, git-archive --remote is actually most of the way there, but it's not an HTTP download, of course. :(

[saagarjha]

GitHub doing something one way and GitLab copying it doesn't make a standard.