I saw this little web app (live demo) by Das Surma going around the other day. It's funny, but it's also a really compelling demo app for a bunch of modern technologies. I'm sure that's the whole point of it.
- Minimal build process. Just Gulp to use Babel and PostCSS. It's heavy on ES6+ and CSS custom properties.
- Loads of custom elements, like
<tinderforbananas-item>, with the Polymer polyfill for those.
- Icons are super tiny SVG, they look hand-golfed.
- ServiceWorker for offline cache.
- Mobile and performance-first design and interactions.
Maybe it'll be like the HTML5 Boilerplate of the future.