> >> It would require your Delphi installation to depend on ICU libraries,
> >
> > Modern Windows do have their own unicode databases.
>
> Firebird uses ICU.

I don't know how modular ICU/C is with regard to transcoding tables.

However, even then, given new Delphi projects spent half-MB just for an icon, i would not think 2-3 MB more would be a barrier.

> If all Delphi strings are Unicode already,

There are still plenty of users stabilized at D5/D7 or D2006
I am working at XE2 now, but people around me work at D2006 and the place i was interviewed before had stock stock-keeping framework written in D5 (which was my D version of choice before XE/XE2).


In D2009+ you have language-default "string" made UTF-16 (http://objectmix.com/delphi/722660-unicodestring-utf16-variable-length-ucs-2-fixed-size.html), yet you still can use any legacy codepage (like 1251 or UTF8, etc) at your choice as well.
http://docs.embarcadero.com/products/rad_studio/delphiAndcpp2009/HelpUpdate2/EN/html/delphivclwin32/System_UTF8String.html
http://docwiki.embarcadero.com/RADStudio/en/How_to_Handle_Delphi_AnsiString_Code_Page_Specification_in_C%2B%2B