font-linking

Is it possible to determine the fonts Windows chooses for font-linking?

Suppose you have a string with text in two or more scripts. When you use a GDI function like TextOut, (modern versions of) Windows will do "font-linking". That is, GDI will draw what it can with your selected font and draw the rest in an appropriate font that it chooses automagically. For example, if part of your text is in English (u...

How do specific browsers prevent downloaded fonts from being available to other applications

As this is a stated requirement of the Web Fonts specification can someone explain to me how individual browsers handle this? I understand that IE temporary installs the font only for the period the font is required, but can find no mention of how this is handled for Firefox, Safari, Chrome, Opera etc. Thanks, ...