JS utils and polyfills.
For the pros:
npm install abo-utils --save
import ABOUtils from 'abo-utils';
For the rest of us:
<script src="https://unpkg.com/abo-utils"></script>
<script>
ABOUtils.DOM.createElement('h2#test.bada.bing', document.body).textContent = 'Hello world!';
</script>
The MIT license - see the LICENSE.md file for details.