I'm not sure how this gets rendered, but the lack of hinting makes it a strain to read. What irony that an article about progress in text rendering has such awful rendering quality. PS: That is in Firefox. In Chrome it uses what appears to be a bitmap font, which is much worse.
I got annoyed that the page hijacked right click and key navigation, so I wanted to print to PDF — which didn't work. Chrome printed a single blank page. Firefox managed to print, but also only a single page, and when zoomed in the font got interpolated (= blurry), instead of being more readable.