HTML5 Sugar

This sugar adds autocompletion for HTML5 tags and attributes.

Install using Git

Open Terminal.app

cd ~/Library/Application\ Support/Espresso/Sugars/
git clone git://github.com/minimalweb/HTML5.sugar.git

Install manually

Download the source and uncompress it. Rename the resulting folder to HTML5.sugar and put it in YourHomeFolder/Library/Application Support/Espresso/Sugars/.