Cardio
Cardio is a web application health tool. It provides a snapshot (via a bunch of metrics) of how "healthy" your application is by measuring HTML/CSS/JS complexity.
Installation
npm install -g cardio
If you get installation errors for node-canvas, don't despair. It's an optional dependency used by Assetgraph to do some other cool stuff that isn't used in Cardio.
Usage
$ cardio »url-or-webroot-or-html-file« > output.json
$ cardio-report2array output.json # Reformats for metrics-friendly digestion