Background Tabs
UPDATE: Background Tabs is no longer developed -- as of Firefox version 64, you can set the about:config preference browser.urlbar.ctrlCanonizesURLs to false and use ctrl-shift-enter to open tabs in the background. This won't work for the search bar. A feature request for that is here. Unfortunately, there is no longer a way (that I'm aware of) to implement background tabbing in recent versions of Firefox via an extension.
Background Tabs is a Firefox extension that enables searches from the search bar or entries to the URL bar to open in background tabs by using the [CTRL] key when hitting [ENTER]. (Current versions aren't working from the search bar, though -- might be a Firefox bug...)
Donations are welcome! (No account is required! -- just click the hard-to-see "Continue" if you have no PayPal account.)
Latest version: 1.973 -- supports 3.5 - 52a2.* and probably higher
Available for download at addons.mozilla.org
Or, they haven't updated yet, you can download the latest version here.(click and then choose "open with Firefox" -- you may first need to go into about:config and disable "xpinstall.signatures.required" -- for versions past 50, you may have to install the developer edition, disable the signatures requirement, and then install... sorry, not my fault. :-)) Comments/suggestions/bug reports welcome!
With this extension, holding [CTRL] or [command] (meta key) when you hit [ENTER] will cause the new tab to be opened but not switched to. I find this crucial for when I want to keep reading a web page but want to make tabs in the background for later reading (e.g. looking up words, starting searches form the search bar, simulating a "CTRL-click" on a link without using the mouse, etc.) This extension will let you open all those tabs in the background and not have to do all the switching of tabs to get back to where you were.
It also works when CTRL-clicking on the search magnifying glass icon or clicking the "go" icon to the right of the URL bar.
Normally, when you enter something in the URL bar or search bar and hit [ENTER], it replaces the current tab's contents, and if you hold down [ALT] when you hit [ENTER], it will open the contents in a new tab, and it will switch to that tab. I wanted a third functionality using the CTRL key.
If you use the extension Stay Open Menu you will probably want to go into the preferences for that add-on and disable it for the "Smart Location Bar" or some key combinations may not work.
People used to the IE-style where the [CTRL] causes prefixes/suffixes to be added to the typed-in phrase will notice that functionality gone.
Note that there is a hidden browser preference called "browser.search.openintab". It defaults to false. If you set it to true, then the behavior of this extension stays the same, but the normal [ALT] modification reverses with respect to [ALT], in terms of searches from the search bar. (Note - I haven't tested this recently).
(The setting available at Preferences->Tabs->"When I open a new tab, switch to it immediately", a.k.a. "browser.tabs.loadInBackground", which affects the behavior of [CTRL]-clicking URLs in pages, may also play into things, but I don't think so...)
Rather related Mozilla bug: https://bugzilla.mozilla.org/show_bug.cgi?id=237027
Possible future features:
- the ability to change which key combinations do what
- the ability to have the default (no key) action be changed as well