How will a web application with XHTML 1.1 and frames behave on major browsers?

Question

I am working on a web application which was built on XHTML 1.1 and also uses frameset and frames. Now the application runs only on IE (upto IE 8). I am trying to make changes so that it runs on major browsers. I have following questions:

1. Is XHTML 1.1 supported on major browsers and is it according to W3C standards?

2. I read that frames are obsolete in HTML5 but if I use XHTML 1.1 then are frames going to work in all browsers?

3. Is there any change in XHTML since XHTML 1.1 which I should incorporate?

Answer 1

1. Yes.

2. Framesets are neither valid in HTML5 nor XHTML 1.1, but they will continue to work in major browsers for compatibility reasons. If you need to use a frameset and want your document to validate you need to pick a document type that includes them such as XHTML 1.0 Frameset.

3. There is just XHTML5, which is nothing more than HTML5 written like XHTML, complying with the syntax rules as given by XML. But as mentioned in the comments, unless you go out of your way to serve your pages as XHTML you are never really authoring or serving XHTML, so you may as well stick with the more permissive syntax rules that come with the HTML syntax of HTML5.

Answer 2

There is XHTML5 (the XHTML syntax for HTML5). Specification, good blog post, another good blog post.

In essence, you can write HTML5 as if it was XHTML, by sticking to several rules.