Side Tabs in Firefox 66
I've become so used to using side tabs (TreeStyleTabs) in Firefox, that it's somewhat painful to use any other browser in more than a passing manner. My work laptop was just replaced, and I had to back into this configuration again, so I figured this is a good time to document it. Drawing from several sources (linked at the bottom). In a terminal window, create your chrome Firefox profile directory: mkdir -pv ~/Library/Application\ Support/Firefox/Profiles/*.default/chrome and your personal chrome file: touch ~/Library/Application\ Support/Firefox/Profiles/*.default/chrome/userChrome.css Install the TreeStyleTab plugin ( https://addons.mozilla.org/en-US/firefox/addon/tree-style-tab/ ) In Firefox, Press Cmd + Opt + I Click on the cog icon (Settings) in the upper right (may be inside the hamburger menu) In Advanced Settings, check "Enable browser chrome and add-on debugging toolboxes" and "Enable remote debugging" Restart Firefox Press Cmd + Opt + Shift + ...