7 ms·For anyone missing Arc's sidebar-based tab management, Tree Style Tab is quite good in Firefox.by kevingadd 3y agoFor anyone missing Arc's sidebar-based tab management, Tree Style Tab is quite good in Firefox.esperent 3y agoI think the Tree Style Tabs extension is considerably older than Arc.qrobit 3y agoAt least both the extension(tst) and the browser (firefox) are open-source. And you can use firefox on any desktop platform including BSDs while arc is limited to MacOS and Windows