Using jQuery with Windows 8 Metro JavaScript App causes security error

You need to edit the jQuery source so that you pass the jQuery.support function to MSApp.execUnsafeLocalFunction, which disables the unsafe content checking, like this:

jQuery.support = MSApp.execUnsafeLocalFunction(function() {

    var support,
        all,
        a,
        select,
        opt,
        input,
        fragment,
        tds,
        events,
        eventName,
        i,
        isSupported,
        div = document.createElement( "div" ),
        documentElement = document.documentElement;


    // lots of statements removed for brevity

    return support;
});

You need to remember to remove the last pair of parenthesis – you don’t need a self-executing function because execUnsafeLocalFunction automatically executes the function it is passed.

I suggest that a better approach is to use the WinJS features – this includes the WinJS.Promise object as an alternative to deferred operations (which are themselves an implementation of the Promise pattern). And you can do some basic DOM manipulation using the WinJS.Utilities namespace.

You should think twice about using jQuery for deferred operations. The WinJS.Promise object is used throughout the Metro APIs to represent async activities and you will end up using two similar-but-different approaches.