Ok, this is a weird one.
I've got a Domino 8.5.3FP3 with UP1 installed and regardless what I try on that server - localStoraget.setItem doesn't work in IE10!
I've got an empty database with an empty XPage inside it and I use the console to issue: localStorage.setItem("test","ok")
This works in IE8 & IE9 on that same server, but not on IE10. (Using IE10 to emulate IE9 or IE8 doesn't work)
On Domino 8.5.3 & IE10 I get the error message: "Function expected"
Using my local dev machine (Domino 9) the same database works.
(IE10 localStorage works on any other page, like google.com for instance).
I've compared the source AND HTTP headers using Fiddler and the only difference I can find is that Domino 8.5.3 uses lowercase for utf-8, where as Domino 9 will output: UTF-8
You can view the comparison here: https://dl.dropbox.com/u/9681254/question/comparingDominoVersions.png
Ideas?
Thanks!
/J