When I try to change Layout of blogs on Blogger, those popups are always opened as new tab. I disabled some and re-enabled addons, then I found out this is about Vimperator. It always overrides browser.link.open_newwindow.restriction with value 0. Which caused the popups open as in a new tab. No matter how you manually reset or issue a command :set popup=2 in Vimperator, that goes back to 0 after Firefox restarts.



After read the :help, Vimperator does support a configuration file, ~/.vimperatorrc. That functions like a .vimrc. Simply write your commands in, so I have

set popups=2
in ~/.vimperatorrc.



RTFM is the solution.