No longer needed Rated 3 out of 5 stars
Firefox has this function built-in now.
3 stars because when it was needed, it did not stop tabs from loading automatically on startup. Moreover Firefox and Chrome have a glitched tab bar that erases the URL if you press stop before the tab begins loading. Opera doesn't have this issue btw.
Yes, I've already made it clear in the description that it's no longer needed. But there are still some people using older versions of Firefox who find this useful.