Click the 
button to pull out current tab into new window.
This extension is just a temporary solution until Opera makes it possible to drag tab to it’s own window
Works in Opera 15 and newer
Install on Opera 15+ »
This was “temporary” fix extension meant for the early Opera versions with the chromium kernel.
I believe newest versions of the browser support this out of the box so it should be pretty curious legacy extension.
Tab to Window
Last update: 12 Sep 2013