Daring Fireball heaps scorn on the implementation of tabs in Safari 15:
From a usability perspective, every single thing about Safari 15’s tabs is a regression. Everything. It’s a tab design that can only please users who do not use tabs heavily; whereas the old tab design scaled gracefully from “I only open a few tabs at a time” all the way to “I have hundreds of tabs open across multiple windows”. That’s a disgrace.
In a footnote, Gruber mentions that the new tabs break conventions stemming from the start of tabbed browsing, 20 years ago.
But tabs have a longer history than that: researchers began to explore tabs before the Web was invented. I used tabs in a 1986 paper for the Intl Technical Communications Conference, though my tabs were landmarks in the document — what we'd now do with breadcrumbs or a hamburger menu, and my tabs were usually beneath the text pane rather than above it. But I don’t think I invented the “tab” metaphor: I think I got it from an electronic encyclopedia project by Ben Shneiderman and Alan Borning at the University of Maryland. Shneiderman’s lab was responsible for a ton of important UI/UX work. I believe NoteCards at Xerox PARC had tabs, too, and NTERGAID (then called Black Magic) did as well. (I did coin the term “breadcrumb”, but I’m pretty sure my tabs were taken from earlier systems.)
The evolution of the modern browser tab is closely tied to the question, “what precisely does the back button do?” What is the difference between a browser tab and a bookmark? A tab has a browsing history, a record of your trajectory. A bookmark is just a record of a place to go. Getting this right was tricky: you’d think the right answer was obvious, but it there were tons of plausible alternatives and, of course, only a relative handful of people who had systems that were browsable before the 90s. One of the top students of the backbutton question was Michael Bieber at NJIT.