What about nonfree HTML and CSS? These are not programming languages, but they are still instructions that tell the browser how to display the page. JS code is

What about nonfree HTML and CSS? These are not programming languages, but they are still instructions that tell the browser how to display the page. JS code is also a set of instructions that determines how the website should behave. JS is sandboxed, so things that it can do on your computer are limited, just like HTML/CSS. Perhaps the issue with JS is that it's still too powerful and it would be great if browsers could let to limit what it can do even more by allowing to set individual permissions for Web APIs.