This is very cool, great work! Although I think you should make it clear in the read me that it only supports 2 basic jQuery-like selectors (by id '#id' and by

This is very cool, great work! Although I think you should make it clear in the read me that it only supports 2 basic jQuery-like selectors (by id '#id' and by class '.class'), ie: none of the following will work - 'div', '[name="test"]', '.class1.class2', '.class1 .class2', 'div.class .class2[data-test="thing"] > em#id:last-child' - I realise that last one should never be used in real life. Some of these could be implemented with things like getElementsByTagName, getElementsByAttribute, and recursive calling when spaces are found. I may even do a pull request with these if I find time this weekend :) Have you looked into using querySelectorAll? I'd be interested to know if it's slower and by how much.