[swills]

Am I the only one who remembers the old tab groups that were removed before these new tab groups were added?

Edit: Ah, it seems Mozilla remembers: https://web.archive.org/web/20151112023150/https://support.m... (linking archive.org in case they take it down, this is the first copy I can find)

[glenstein]

Right, Mozilla was actually first on the block with this. And even when they removed it it was available as an extension, because their extension ecosystem was capable of UI-level changes.