Unless you mean something else, locale support was already introduced in AmigaOS 2.1.
And I'm not sure what you exactly mean by "did it right". i18n and localization support is now in every OS and almost any UI framework available today.
It was really great for its time but I wouldn't know of any feature it had that isn't standard today.
I never had a 2.1 machine, so I was mistaken there. Thanks for correcting that.
To the point, I think the way the Amiga let a third party provide a localization file was easier than in todays OS more end user friendly. It was open and standardized across the OS. Not every app was cooking it's own format.
And I'm not sure what you exactly mean by "did it right". i18n and localization support is now in every OS and almost any UI framework available today.
It was really great for its time but I wouldn't know of any feature it had that isn't standard today.