Install FreeBSD, tabs(1) is still a thing! It's interesting that FreeBSD man says "A tabs utility appeared in PWB UNIX," while Wiki refers PWB/UNIX as having its initial release in 1977.
PWB Unix was the earliest sources I could find. FreeBSD lists history items for releases going back to the earliest unix release because BSD Unix is derived from AT&T Research Unix and FreeBSD is derived from 4.4BSD...
The tabs file does predate this, and I'll make a note of that (which is what this article is about).