[hanniabu]

Browsers should also come packages with the most popular is libraries like jQuery, bootstrap, vue, d3, etc (not a real list, just off the top of my head)

[ahoka]

Already possible: https://www.localcdn.org/

[hanniabu]

That's an extension

[wizzwizz4]

That's an implementation detail. Several parts of Firefox and Chrome are implemented internally as extensions.

[robertlagrant]

We already have CDNs so one site downloading a version of a library works for all. Maybe content-addressible dependencies could make that even better, for cross-CDN support?

[MortyWaves]

No it doesn’t, CDNs now very specifically are not able to download it for all sites like they used to. Chrome saw to this.