Looking at the Icelandic layout[1] from a programmers' perspective, the big difference appears to be that \, [, and ] need a modifier, Alt-Gr; and ; (semi-colon) is shifted.
The shifted semi-colon must be irritating in C-like languages, but even on US/UK keyboards, characters like ( and { need Shift, which admittedly is larger than Alt-Gr and there are two of them.
I wonder if the larger right Shift key can be mapped as Alt-Gr.
PS. Does Icelandic need the letter 'mu' often enough to dedicate a key to it on the keyboard?
μ is used a fair bit by anyone who uses the metric system, so it makes sense to include it. It's used as a prefix to denote a millionth for those that don't know, as in µm = micrometer = a millionth of a meter.
It's mapped to Alt-Gr+M on Swedish keyboards as well, but I've never seen a keyboard where it's actually written on out on the key.
> A fair bit by anyone who uses the metric system?
I'm sorry, but what?
Most people who use the metric system can't tell you which is smaller: micro or milli. Most people will never encounter anything in their lifetime they will actually need to reason about in some important manner that is measured in μ-anything.
As a user of the Icelandic layout I wasn't even aware that the key was on there, but I can confirm that we absolutely don't need it. I think there are probably a lot of keyboard layouts that could use modernizing wrt. how they are actually used today.
µ would be used by scientists, engineers, doctors and nurses.
That doesn't seem unreasonable, when we have <, >, { and } for mathematics, \ originally for logicians (to combine to make /\ AND and \/ OR) and |, @, _ and # for programming.
Shifted semicolon is absolutely a non-issue. If there are any problems with the layout, it's hiding the symbols behind altgr, but the shifted semicolon is really not a problem.
I think if my mother tongue wasn't English, and I therefore regularly typed on a different European layout, I'd remap the left Windows key or maybe Caps Lock to be an additional AltGr.
I disagree. I have been writing code with the icelandic layout for over 20 years and it has really never been an issue for me. You put your right thumb on altgr and hit the number keys.