Comment by breve

> For instance the Mozilla DOM experiments seems to use a special JS variant with a 'use component' header

As per the article, that's temporary until Component Model 1.0 is implemented natively in the browser. In the meantime, jco can be used:

> The groundwork for browser implementations is being laid today: jco’s transpile command already converts any component into equivalent core Wasm and JavaScript glue, making components runnable in any browser without native support.

That's no longer needed once native support is there.