I think this is the bug for implementing a sidebar API: https://bugzilla.mozilla.org/show_bug.cgi?id=1208596 https://bugzilla.mozilla.org/show_bug.cgi?id=12085

I think this is the bug for implementing a sidebar API: https://bugzilla.mozilla.org/show_bug.cgi?id=1208596 https://bugzilla.mozilla.org/show_bug.cgi?id=1208596 It doesn't seem to be getting much traction so far -- maybe jump in and encourage? Chromium has wontfix-ed their sidebar API: https://bugs.chromium.org/p/chromium/issues/detail?id=344870#c113 https://bugs.chromium.org/p/chromium/issues/detail?id=344870... https://bugs.chromium.org/p/chromium/issues/detail?id=51084#c99 https://bugs.chromium.org/p/chromium/issues/detail?id=51084#... https://bugs.chromium.org/p/chromium/issues/detail?id=477424#c82 https://bugs.chromium.org/p/chromium/issues/detail?id=477424... I was sad to see that -- Tree Style Tabs is the killer Firefox feature for me. Maybe if Firefox can show the sidebar API works it'll get another hearing with Chrome as well.