> Will every browser load xhtml?? do I mark the page index.html or
Yes. All browsers will load and display XHTML, all the way back to IE and
NS 3.x. It even loads and displays just like HTML.
You can leave your *.html extension, or *.htm., or *.shtml, or *.php, or
whatever. XHTML doesn't care what extension you use.
Using XHTML has more impact on your CSS because its proper implementation
determines whether or not the browser will use quirks or strict mode to
display the page.
Personally, I always use valid XHTML and valid CSS. In most browsers (I
think the vast majority), this triggers strict rendering mode, which is
just fine by me.
I do believe there was one or two rebellious browsers that insist on
rendering wonderfully valid code in quirks mode, anyway, but I can't
remember the browser's name. I think I chose to ignore that issue entirely
and pray no one complained.