Redmine

It wold be very useful to temporarily be able to get rid of the menu and sidebar and see the content only. This could be done by being able to switch the content area to fullscreen using html5 browser support.

In newer browsers such as Chrome 15, Firefox 10, Safari 5.1, IE 10 this is possible. Here's how to do it:

function requestFullScreen(element) {
    // Supports most browsers and their versions.
    var requestMethod = element.requestFullScreen || element.webkitRequestFullScreen || element.mozRequestFullScreen || element.msRequestFullScreen;

    if (requestMethod) { // Native full screen.
        requestMethod.call(element);
    } else if (typeof window.ActiveXObject !== "undefined") { // Older IE.
        var wscript = new ActiveXObject("WScript.Shell");
        if (wscript !== null) {
            wscript.SendKeys("{F11}");
        }
    }
}

var elem = document.body; // Make the body go full screen.
requestFullScreen(elem);
The user obviously needs to accept this fullscreen request first.

Read more:

https://developer.mozilla.org/en/DOM/Using_full-screen_mode

Native Fullscreen JavaScript API