Hello, I am trying to use Firefox (v24.4.0 ESR) in HTML5 full screen mode with either two screens or a tiling window manager. The problem is, whenever the browser window looses focus, Firefox leaves full screen. It seems that it was possible to remedy this problem by setting 'full-screen-api.exit-on-deactivate' in 'about:config', but only until Firefox version 21.0 [1]. The option is not there anymore and even creating it manually doesn't work. Searching the web did not yield any way to achieve this in a recent Firefox version. Does somebody know of a way to get Firefox to stay in full screen when leaving focus? [1] http://cat-in-136.blogspot.com/2013/06/diff-between-firefox-220-beta-3-default.html