Update: As of version 11.50, control-click opens the new tab in background, as desired. Yay!
In Opera, as opposed to all other modern browsers I know, control-click does not open a new
tab. Moreover, I couldn't find any good way to configure this behavior. The best
available option seems to be this. However, it's so hacky that it won't work on HTTPS sites unless you enable user javascript there, which doesn't seem like a good idea. There also seem to be other proposed solutions, but none of them seem to work.
I'd like this because my laptop has no middle mouse-button, and I'm a creature of habit.
Do people have any ideas (for the latest version, 10.50)? I'd like ctrl-click to open a background tab, but I can do with foreground. Thank you!