Awesome

corslite

corslite('http://b.tiles.mapbox.com/v3/tmcw.dem.json', function(err, resp) {
    // resp is the XMLHttpRequest object
}, true); // cross origin?

an AJAX library focused on simplicity and supporting IE8-10 with cross domain requests.

We're making a deal with the devil and using XDomainRequest in hopes that it is less a hack than JSONP. This comes with caveats:

• No headers are permitted on requests
• Only 'GET'
• No access error diagnostics (status code, response body) on IE