[maverick74]

KDE Plasma also had this many years ago (before Windows' Sets), but they ended up removing it in Plasma 5.

(there is a bug report about it: https://bugs.kde.org/show_bug.cgi?id=343690

)

[olejorgenb]

I think pwm/ion3 (now notion) was (one of?) the first WM for linux supporting tabs. Released in 2000. https://en.wikipedia.org/wiki/Ion_%28window_manager%29#/medi...