Disable LESS.js caching

file.html

<!-- CLIENT-SIDE SCRIPTS: BEGIN -->
<script>
    var less = {
        env: "development"
    }
</script>
<script src="//cdnjs.cloudflare.com/ajax/libs/less.js/1.4.1/less.min.js"></script>
<script>window.less || document.write('<script src="/js/vendor/less-1.4.1.min.js"><\x3C/script>')</script>
<!-- CLIENT-SIDE SCRIPTS: CLOSE -->

Notice the LESS environment declaration BEFORE including less.