Let's not let this discussion sidetrack into "shared hosting vs VMs (vs docker?)" --- there's another phabricator ticket and summit topic for that ( https://phabricator.wikimedia.org/T87774 and https://phabricator.wikimedia.org/T113210.
I'd prefer to have discussion in *this* particular task/thread concentrate on:
* Hey, we can have JavaScript and PHP in the same packaging system. What cool things might that enable?
* Hey, we can have JavaScript and PHP running together in the same server. Perhaps some persistence-related issues with PHP can be made easier?
* Hey, we can actually write *extensions for mediawiki-core* in JavaScript (or CoffeeScript, or...) now. Or run PHP code inside Parsoid. How could we use that? (Could it grow developer communities?)
* How are parser extensions (like, say, WikiHiero, but there are lots of them) going to be managed in the long term? There are three separate codebases to hook right now. An extension like <gallery> might eventually need to hook the image thumbnail service, too. Do we have a plan?
And the pro/anti-npm and pro/anti-docker and pro/anti-VM discussion can go into one of those other tasks. Thanks.
--scott