Given the context here, however, I should note that the Menu key is purely equivalent to right clicking on what’s focused or selected or where the caret is in a text box, to open the context menu, which sounds fairly different from the Xbox controller’s Menu button (though I’ve never used it). As for the context menu, web pages should never touch it, and web apps shouldn’t often. I’m still sad about the death of <menu type="context"> which let you add to the native context menu. Now your only options as a web app are to leave the native context menu alone, or completely replace it, neither of which are great options, a lot of the time.