For example, Firefox allows users to change the color of webpage backgrounds, should the page not specify it. This is extremely useful in situations like my own, where my monitor's brightness can't go down any more, but when I'm working on other things, the default webpage background of pure white is brighter than I'd like it. I set Firefox's background to be a light gray, because it isn't as harsh on my eyes, but it also works well with most webpages, since most text is black. Also, this can save a fair amount of energy over time, especially if you multiply by all the individuals who could take advantage of this feature. It's a win-win!

Why does Opera not let me click anywhere at the top of the maximized window to move the window anymore? Or am I missing something?

For example, Firefox allows users to change the color of webpage backgrounds, should the page not specify it. This is extremely useful in situations like my own, where my monitor's brightness can't go down any more, but when I'm working on other things, the default webpage background of pure white is brighter than I'd like it. I set Firefox's background to be a light gray, because it isn't as harsh on my eyes, but it also works well with most webpages, since most text is black. Also, this can save a fair amount of energy over time, especially if you multiply by all the individuals who could take advantage of this feature. It's a win-win!