XHTML Club

Circa '99 a high fraction (50%-ish) of HTML in the field was invalid, so if you were making a new web browser it had to parse invalid HTML the same way as Netscape which was one more reason we didn't get competitive web browsers.

HTML 5 specified exactly how "invalid" HTML is parsed so now there is no such thing as invalid HTML. XHTML was one of those things that never quite worked:

https://friendlybit.com/html/why-xhtml-is-a-bad-idea/

It’s ironic that the very site in question, despite claiming XHTML compliance, is served as text/html instead of application/xhtml+xml, so the browser will never parse it as XML.

To quote [0]:

> All those “Valid XHTML 1.0!” links on the web are really saying “Invalid HTML 4.01!”.

Although the article is 20 years old now, so these days it’s actually HTML5.

Edit: Checked the other member sites. Only two are served as application/xhtml+xml.

[0]: https://webkit.org/blog/68/understanding-html-xml-and-xhtml/

I was in college when XHTML was all the rage and everything we wrote had to pass validation. I still get uncomfortable adding breaks without closing them.

> Validation is ignored, and most modern sites are built with little concern for structure or longevity.

I remember going online with a modem in the 90s. There was a new ISP in town, but their homepage took forever to load. I viewed the source, and whatever page generator they were rendered the page as HTML tables (this was fine back then), and added repetitive style tags to every table cell instead of using CSS (although I wonder if this was before CSS) or not doing so for empty cells, and that their homepage was so bloated and slow to load on dial-up.

I wonder how it is nowadays. But I suppose in the age that accomodates apps like Teams and Slack, who cares?

I used to create a number of simple web pages in XHTML back in the days when we believed XHTML was the future. Recently, while going through and restructuring some of my old "online stuff", I learned that XHTML really isn't in a state that I'd want to use it any more:

* XHTML 1.0 and 1.1 are officially deprecated by the W3C.

* XHTML5 exists as a variant of HTML5. However, it's very clear that it's absolutely not a priority for the HTML5 working groups, and there's a statement that future features will not necessarily be supported by the XHTML5 variant.

* XHTML5 does not have a DTD, so one of the main advantages of XHTML - that you can validate its correctness with pure XML functionality - isn't there.

* If you do a 'view source' in Firefox on a completely valid XHTML 1.0/1.1 page, it'll redline the XML declaration like it's something wrong. Not sure if this is intended or possibly even a bug, but it certainly gives me a 'browser tells me this is not supposed to be there' feeling.

It pretty much seems to me XHTML has been abandoned by the web community. My personal conclusion has been that whenever I touch any of my old online things still written in XHTML, I'll convert them to HTML5.

In the early 2000s I was 100% sold on the idea of strict XHTML documents and the semantic web. I loved the idea that all web pages could be XML documents which easily provided their data for other sources. If you marked your document with, an XHTML 1.0 Strict or XHTML 1.1 doctype, a web browser was supposed to show an error if the page contained an XML error. Problem was, it was a bit of a pain to get this right, so effectively no one cared about making compliant XHTML. It was a nice idea, but it didn't interact well with the real world.

Decades later, I'm still mildly annoyed when I see self-closing tags in HTML. When you're not trying to build a strict XML document, they're no longer required. Now I read them as a vestigial reminder of the strict XHTML dream.

EDIT: I just checked, and my site (at least the index page) still validates! https://validator.nu/?showsource=yes&doc=https%3A%2F%2Fander...

EDIT2: Hey, look, if you still want to use self-closing tags where they're not required: go nuts! I'm just explaining why I don't use them anymore.

In the linked article:

> you should master the HTML programming¹ language

The footnote reads:

> 1. This is a common debate - but for simplicity sake I'm just calling it this.

It's not really a debate, HTML is a markup language [1], not a programming language: you annotate a document with its structure and its formatting. You are not really programming when you write HTML (the markup is not procedural) (and this is not gatekeeping, there's nothing wrong about this and doesn't make HTML a lesser language).

To avoid the issue completely, you can phrase this as: "you should master HTML" and remove the footnote. Simple, clean, concise, clear. By the way, ML already means "Markup Language", so any "HTML .* language" phrasing can feel a bit off.

[1] https://en.wikipedia.org/wiki/Markup_language

I would really like to use XHTML. It would make my HTML emitter much simpler (as I don't need special rules for elements that are self-closing, have special closing or escaping rules and whatever else) and more secure.

However no browsers have implemented streaming XHTML parsers. This means that the performance is notably worse for XHTML and if you rely on streaming responses (I currently do for a few pages like bulk imports) it won't work.

Valid pure HTML 4.01 (1) made in 2025 counts?

I don’t thing it’s about luddites as website mentioned. Many professions have tools suggesting that person have extensive experience and in terms of web development, XHTML 1.0 or old standards of HTML are such.

1. https://www.tirreno.com