I think the idea would be that when you click on a link to a 25 year old page, the browser brings up a little warning saying "This page is 25 years old and has some errors that may stop it displaying correctly. Press the Refresh button to re-render it using an older browser engine."
In the worst case, the browser would then have to download some additional code that contained all the support for invalid HTML/CSS code. In the best case, the 25 year old page would be served with a header containing a cryptographic proof that the site really had been around for 25 years, and it wasn't just some newly created attack site that was exploiting some weird behaviour in old renderers.
In the worst case, the browser would then have to download some additional code that contained all the support for invalid HTML/CSS code. In the best case, the 25 year old page would be served with a header containing a cryptographic proof that the site really had been around for 25 years, and it wasn't just some newly created attack site that was exploiting some weird behaviour in old renderers.