[piaste]

US-intl can do that just fine, though some people can't stand dead keys.

[Symbiote]

Whether dead keys are acceptable or not depends heavily on how frequent they are in the language.

The Danish keyboard layout has ¨, ^, ´ and ` on dead keys — those are used in foreign names and a few loanwords — but Æ, Ø, Å are real keys.

Having Å, Ø and Æ as dead keys would make as much sense as having V, K and J as dead keys in English.

[piaste]

I use it to type in Danish and Italian, as it happens (plus Swedish and French every now and then).

Æ, Ø, Å aren't dead keys, they're available via AltGr + Z, L, and W respectively. However, Italian and French accented letters (as well as Swedish/German Ä/Ö) are available via either AltGr or dead keys - and I find myself almost always using dead keys, perhaps because they are more "logical" so I learned them faster.

And of course, typing any kind of quote is a dead key in every language (quote followed by spacebar).

By now, after so many years, dead keys are well in muscle memory so they feel barely any slower to type than regular two-key combos (like uppercase letters).