[gwern]

> While isolation had a great deal to do with this initially, nowadays it's mostly because of the work of the Icelandic Language Institute, which religiously updates the language to add new words for concepts that didn't previously exist.

That sounds a lot like the French Academy; but so far as I know, French has precipitously changed quite as incomprehensibly as English, and has not remained stable (save for an expanded vocabulary) as you say Icelandic has. Why do you think the Institute succeeded and the Academy failed?

[carnevalem]

Perhaps number of speakers? Icelandic only has 320,000 speakers. I suspect it would be easier to control the direction of a language with that many speakers compared to French's 200,000,000.

http://en.wikipedia.org/wiki/Icelandic_language http://en.wikipedia.org/wiki/French_language

[mseebach]

I would guess the relative isolation of Iceland for a very long time is also a factor. While the French constantly mixed with pretty much all European peoples during medieval times, receiving an influx of things and concepts in need for a word, the number of people crossing the borders of Iceland was very limited, for practical reasons.