17:52
<hsivonen>
Firefox only implements https://tc39.es/ecma402/#sec-lookupmatchinglocalebyprefix . I hear from sffc that Chrome doesn't implement it and only delegates to ICU4C's lookup as https://tc39.es/ecma402/#sec-lookupmatchinglocalebybestfit . What does Safari do for lookup?
18:24
<hsivonen>
It looks to me that Chromium does have two distinct lookup algorithms.
19:17
<hsivonen>
Looks like WebKit/JSC does what Gecko/SpiderMonkey does.
19:17
<hsivonen>
I.e. https://tc39.es/ecma402/#sec-lookupmatchinglocalebyprefix only.