Icelandic is, I believe, a Germanic language dating back to the 1200s or so.
What I think you're getting at - and one of the cool things about Iceland - is that the language hasn't changed all that much since it was introduced back then. This means that modern Icelanders can read the Sagas (written in the 10th and 11th centuries) with relative ease. The majority of people will read them in the same way we read Shakespeare or Dickens (with modern spelling and some footnotes), but with some effort they can be read by most well-educated Icelanders in their initial forms.
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. They also work with the Icelandic Naming Committee, to maintain the list of acceptable first names that Icelandic children can be given - if the name you want to give your child isn't on the list of previously-used names, you have to submit it to the Committee to make sure that it is appropriate (i.e. can be spelled in the Icelandic alphabet and fits into Icelandic grammar).
Another important factor is density of population.
Over 500 years ago, the people in Sweden and Denmark spoke East Scandinavian, which was one language, but that had a "dialect continuum" from south to north. But in the 1500s, Sweden gained independence, and both countries adopted protestantism, which meant both countries translated the bible. And with that action the languages actually split with Danish gravitating towards how it was spoken and spelled in Copenhagen, and Swedish gravitating towards how it was spoken and spelled in Stockholm.
So Swedish and Danish are almost the same language, they've only been split for 500 years. But since Denmark is a more densely populated country, it means that Danish has changed faster. Swedish has been going through similar transformations as Danish, except slower.
For example, Danish has gone further in vowelshifting y to ö, compare the word for key: "nyckel" in Swedish, "nøgel" in Danish. In some Swedish dialects people say "nöckel", but it hasn't made it to standard Swedish.
Both languages have done consonant softening of g to j and k to g or ch, but Danish has also softened t to d, v to u, and p to b.
And the sole reason for this is that Denmark has a six times higher population density than Sweden, with roughly the same population.
Although the other theory on Danish language, namely that they've all stuffed their mouths full of potatoes before speaking, is still somewhat plausible. :-)
> 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?
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.
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.
> 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
An Icelandic colleague told me that the Icelandic word for computer is "Tölva", stemming from tala and Völva, respectively "number" and the name for a kind of female prophets from Nordic mythology. I could get behind this, much more than the (failed) Danish attempt to call it a "datamat" (from data and automat).
What I think you're getting at - and one of the cool things about Iceland - is that the language hasn't changed all that much since it was introduced back then. This means that modern Icelanders can read the Sagas (written in the 10th and 11th centuries) with relative ease. The majority of people will read them in the same way we read Shakespeare or Dickens (with modern spelling and some footnotes), but with some effort they can be read by most well-educated Icelanders in their initial forms.
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. They also work with the Icelandic Naming Committee, to maintain the list of acceptable first names that Icelandic children can be given - if the name you want to give your child isn't on the list of previously-used names, you have to submit it to the Committee to make sure that it is appropriate (i.e. can be spelled in the Icelandic alphabet and fits into Icelandic grammar).