this event is only supported by Internet Explorer 10 and 11. Indie UI events Not yet really implemented, the Indie UI working groups want to help web application developers to be able to support standard user interaction events without having to handle different platform specific technical events that could match with it. Scripting usable interfaces can be difficult, especially when one considers that user interface design patterns differ across software platforms, hardware, and locales, and that those interactions can be further customized based on personal preference. Individuals are accustomed to the way the interface works on their own system, and their preferred interface frequently differs from that of the web application author's preferred interface. For example, web application authors, wishing to intercept a user's intent to undo the last action, need to "listen" for all the following events: Control+Z on Windows and Linux. Command+Z on Mac OS X. Shake events on some mobile devices. It would be simpler to listen for a single, normalized request to "undo" the previous action. Internet Explorer-specific events In addition to the common (W3C) events, two major types of events are added by Internet Explorer. Some of the events have been implemented as de facto standards by other browsers. Clipboard events. Data binding events. Note that Mozilla, Safari and Opera also support the readystatechange event for the XMLHttpRequest object. Mozilla also supports the beforeunload event using the traditional event registration method (DOM Level 0). Mozilla and Safari also support contextmenu, but Internet Explorer for Mac does not. Note that Firefox 6 and later support the beforeprint and afterprint events. XUL events In addition to the common (W3C) events, Mozilla defined a set of events that work only with XUL elements. Other events For Mozilla and Opera 9, there are also undocumented events known as DOMContentLoaded and DOMFrameContentLoaded which fire when the DOM content is loaded. These are different from "load" as they fire before the loading of related files (e.g., images). However, DOMContentLoaded has been added to the HTML 5 specification. The DOMContentLoaded event was also implemented in the Webkit rendering engine build 500+. This correlates to all versions of Google Chrome and Safari 3.1+. DOMContentLoaded is also implemented in Internet Explorer 9. Opera 9 also supports the Web Forms 2.0 events DOMControlValueChanged, invalid, forminput and formchange. Event flow Consider the situation when two event targets participate in a tree. Both have event listeners registered