Confirm accuracy of required extensions
The list of required extensions originated at https://github.com/cftp/WP-Extension-Check.
I don't believe the filter extension is actually required to run WP, but it's certainly required to run some popular plugins such as Yoast SEO.
Are all the other "required" extensions accurate?
Core doesn't require libxml either I think. We do.
sockets is probably no longer required since Requests was merged in.
See also https://github.com/ataylorme/WordPress-Hosting-Best-Practices-Documentation/blob/master/server-environment/server-environment.md#php-extensions
It might be nice to have aforementioned document link to the specific usage.
Core doesn't require libxml either I think. We do.
Core uses libxml for some stuff if it is available, e.g. XML oEmbed responses.
It turns out there is a core list: https://make.wordpress.org/hosting/handbook/handbook/server-environment/#php-extensions
This list is used in WP_Site_Health::get_test_php_extensions() in the new Site Health functionality in 5.2, unfortunately not very well abstracted.
It turns out there is a core list:
I think the core list is simply a published version of https://github.com/ataylorme/WordPress-Hosting-Best-Practices-Documentation/blob/master/server-environment/server-environment.md#php-extensions
Which I put together originally. To the best of my knowledge, and may not be 100% accurate.