HTML 5 UP - Makes spiffy HTML5 site templates
HTML5 Boilerplate - A rock-solid default for HTML5 awesome.
HTML KickStart - HTML KickStart is a ultra–lean set of HTML5, CSS, and jQuery (javascript) files, layouts, and elements designed to give you a headstart and save you a lot of hours on your next web project.
Materialize CSS - A modern responsive front-end framework based on Material Design