| > browsers simply didn’t use XHTML Do you mean "developers didn't use XHTML"? All browsers implement XHTML. It's referred to as "the second concrete syntax for HTML" in the WHATWG spec.[1] Indeed many websites do use XHTML, the HTML application of XML. However, since proper documents render identically, you won't be aware that you're visiting an XHTML site - that is, unless you check the source. Fun history side note: Browsers like Netscape and Internet Explorer didn't agree on how to parse HTML in the past. They handled omitability differently, for example, in overlapping hierarchies (<p><b></p></b>). To fix this mess, Sir Tim asked well-respected SGML practicioners to create a clean subset of SGML and define a document type definition (DTD) for HTML. They came up with XML, the clean subset, and XHTML, the DTD. [2] Basically, XHTML was the first actual standardization of HTML. Unfortunately, minor syntax errors will prevent a XHTML document from rendering, which, to some degree, is probably why it was never widely accepted by developers. [1] https://html.spec.whatwg.org/multipage/introduction.html#htm... [2] https://www.youtube.com/watch?v=Q4dYwEyjZcY |
Internet Explorer did not. It completely refused to render XHTML pages served with an XML MIME type (application/xhtml+xml). It would only display pages if they were served with the text/html MIME type, which meant that none of XML’s vaunted features (such as strict parsing) came into play, and such pages were effectively treated as “HTML with syntax errors.”
A big part of why WHATWG was able to dethrone W3C was W3C’s insistence on dropping HTML in favor of XHTML when the overwhelmingly dominant browser of the time had zero support for it.
> They came up with XML, the clean subset, and XHTML, the DTD. … Basically, XHTML was the first actual standardization of HTML.
No, the first formal HTML standard was 2.0 (RFC 1866), which was released in November 1995 and had a DTD that among other things disallowed overlapping hierarchies. XML’s first draft was released a full year later (November 1996), and the first W3C spec was XML 1.0 in 1998. Later that year came the initial drafts for XHTML 1.0, which was a straightforward translation of HTML 4.0 to XML.