Comment 6 for bug 891648

Chromium, Firefox & Thunderbird all support both CTRL + TAB as well as CTRL + PAGEUP and PAGEDOWN. I was leaning towards CTRL + TAB because in a unscientific straw poll this seemed to be the most frequently requested option, and also some laptops (e.g. those from Apple) do not have PAGEUP and PAGEDOWN keys. To compare ourselves to the competition, Apple use CTRL + TAB in Safari on OS X, and on Windows both CTRL + TAB and CTRL + PAGEUP and PAGEDOWN are supported.

 As long as there is no conflict with other functionality we could support both (in the same manner as Windows), as it is likely that different sets of users will be already used to one or the other of the options, and this is the approach already taken by our main applications.