The whole article is great, learning about the <canvas> element in HTML.
However, what really struck me was how Heydon describes his process. I've never read something that so closely resonates to my own approach. It's wonderful...and how the whole article opens:
I’m very much a text first kind of designer. I think about content before I worry about aesthetics, and I take care of typography before I attempt any other visual design. The web is primarily for text. Most videos, images, and audio files should probably be text instead. Sure, people won’t read most of your text, but it’s their loss.
After text, I care about HTML. I care about HTML primarily because it helps me format text. And it helps me format text in accessible ways, endowing aural presentations of the text with equivalent structure. HTML is a metalanguage and language primarily means words. Mediated words primarily take the form of written text. HTML is a language for text.
Styling, his own.
He describes my preferred practice & process for developing websites. Even sparked energy to get started on building a friend's company's website, focused on the HTML first.