For instance, you can load up the same static page for everybody, then after it's loaded, serve some small personalized Javascript that refers to your particular user account which then customizes the page.
https://news.ycombinator.com/item?id=41104845
Currently it looks like at least Firefox and Chromium both cache stylesheets and included files as you'd expect. In fact, you can use this to increase cacheability in general. e.g. when this site is having performance issues, it often works logged out/when serving static versions of pages. It's easy to make every page static by including a `/myuser.xml` document in the xsl template and using that to get the current logged in user/preferences to put on the page. This can then be private cached and the pages themselves can be public cached. You can likewise include an `/item-details.xml?id=xxxx` that could provide data for the page to add the logged in user's comment scores, votes, etc. If the included document fails to fetch, it falls back to being empty, and you get the static page (you could detect this and show a message).
I don't follow. How does serving static content imply a requirement for JavaScript?
If anything, serving static content through a CDN means the exact opposite: just have the site point to the resource and let the CDN how the resources are handed over to clients.