We need to create a web page in HTML that will use some Javascript to
load information from several different websites. The good news is
that our HTML, Javascript and CSS files can be installed on a local
disk and opened in the browser.

 I know that it is generally possible to ask for the
UniversalBrowserRead permissions in Mozilla/Firefox and this will give
the code the chance to load the information with XMLHttpRequest.  What
is the best way to do this with IE and Safari? Are there any good
libraries for handling this? Is it worth signing the Javascript? If
so, how would I do that and what would it by me? Can I eliminate all
of the warning boxes that might get old if the page is used repeated?

Thanks.