When I first learned that XSLT was going away, I got curious how to achieve the same thing in JS (client-side templating that happens during page load, without any "flash of content"). It turns out there's a very nice way to do it, by using inline scripts that append elements next to document.currentScript. Lean Rada wrote about it here: https://leanrada.com/notes/inline-rendering-currentscript/ and I wrote about it as well: https://vladimirslepnev.me/write
Shame back in the XHTML days XSLT was a spec that could have made website modularity so much cleaner. I once created an early website creation tool that merged separate components using XSLT it was really powerful in the days before javascript was usable without jQuery. However XHTML was dropped in favor of HTML5 and XSLT was pretty much useless after that. Its done well to survive this long I presume it was mainly kept to style XML files.
HTML5 could have taken the extra step of defining a canonical XML or XML-compatible DOM encoding, or at least encouraged it. But the anti-XML sentiment was explicit and spiteful. Still, popular XSLT processors are built to consume and even produce HTML5, I'm just not sure how thorough those capabilities are or whether they're based on any formal or informal standards. (Maybe the W3C has/had something like that, as part of it's attempts to rollup HTML5 snapshots into versioned standards?)
I lost any enthusiasm for XML after my experience with WDDX and XML-RPC, but as a foundation for HTML it was the best thing going. And maybe still is, given the absence of cross-toolchain contenders? Ditto for XSLT, at least if disregarding the choice to make the syntax homoiconic. In fact I circled back to XSLT long after it was clear it was a dead end. A good tool is a good tool, and the fact it remains so despite the wanton neglect only proves it.
i think xhtml happened before the wider world of web devs were ready for it. Component based architectures took longer to be adopted than I certainly expected.
It might actually work if reintroduced these days as long as we can consider many components to be valid documents.
Yeah, XSLT 1.0 has some really obvious missteps, so much so that to my knowledge basically nobody just implements XSLT 1.0. What they actually support is (most of) XSLT 1.0 plus a handful of EXSLT extensions (which are completely unofficial and not part of any XSLT spec, by the way). In my opinion the EXSLT stuff is the bare minimum needed to make XSLT 1.0 at least a passable language. Meanwhile, the XSLT spec evolved into 2.0 and 3.0, which as far as I'm aware, even to this day, has no complete open-source implementation.
i just got flashbacks to a past life where i handcrafted XSLT to pre-render output from a service as HTML server side. Of course the front end was running some asp.net version and Microsoft flavored XSLT had lots of quirks.
In the age of LLMs I would expect that legacy code bet carried indefinitely. The LLMs will have it indefinitely in their training data, and with code "cheap" to produce now, what are the good reasons for dropping legacy code?
The breakage that sticks out to me is that IIS in Windows Server outputs some reports as XML+XSLT and these have become nigh unusable for years now.
I ignore every official statement about “support” and simply look at the horse's mouth: Microsoft hasn’t bothered to fix this in IIS, and likely never will.
It’s a dead product, “supported” only in a contractual sense, not a practical one.
(If you called support right now demanding fix for this, they’d tell you that it’s broken by design, have you tried moving to a recurring revenue service offering?)
It is wild to look back at XHTML and see that the W3C were entirely correct about XML. They envisaged a world of schemas, client side templating, custom elements, dynamic forms, the works.
Alas, for laughably bad reasons we had to scrap all that for HTML5, Javascript and CSS; a stack so awful that most devs doing anything on the frontend immediately scramble to React, TypeScript, Tailwind, whatever it takes to avoid the underlying garbage.
A horrid state of affairs that will only get worse as time goes on.
The XHTML/XML/XSLT tooling was bad, and XSLT was hard to reason about. That meant that amateurs had no way to learn it, and those amateurs went to school and became the workforce.
The web became a winner because it was easy to get something working. And then Google made it a mission to make great developer tools in everyone's hands for free.
I think in 2026 we could build the tooling around a better experience, but it would require thinking about the developer experience first.
You could do some awesome things with XML/XSL. My favorite was RSS feeds or OPML collections of RSS feeds (both flavors of XML) calling an XSL transformation when viewed in a web browser instead of mined by computers for data; same with TEI files, although that was a bit more arcane. The idea was that you'd have one data file for machine use and a way to present that data to humans as a web page.
But, as a stack, the XML/XSL/XPath/etc combination was weak because XSLT was hard to comprehend and never updated. No browser supports XSLT 2 or 3; they froze support with 1. XSLT 2 was 2007, a year before HTML 5 was a thing, yet it never got picked up by browsers. Javascript was just easier to understand than XSLT. Development of XHTML was also glacial, and people wanted new tags, especially for video.
I can't help but agree, and sometimes I think about the alternate version of the web where XML realized its full potential as the dominant technology. The obvious problem with XML is that the syntax is so verbose and redundant that it's only barely human-writable, but this is 100% a solvable problem.
When I first learned that XSLT was going away, I got curious how to achieve the same thing in JS (client-side templating that happens during page load, without any "flash of content"). It turns out there's a very nice way to do it, by using inline scripts that append elements next to document.currentScript. Lean Rada wrote about it here: https://leanrada.com/notes/inline-rendering-currentscript/ and I wrote about it as well: https://vladimirslepnev.me/write
That Lean Rada article is really fun!
Shame back in the XHTML days XSLT was a spec that could have made website modularity so much cleaner. I once created an early website creation tool that merged separate components using XSLT it was really powerful in the days before javascript was usable without jQuery. However XHTML was dropped in favor of HTML5 and XSLT was pretty much useless after that. Its done well to survive this long I presume it was mainly kept to style XML files.
HTML5 could have taken the extra step of defining a canonical XML or XML-compatible DOM encoding, or at least encouraged it. But the anti-XML sentiment was explicit and spiteful. Still, popular XSLT processors are built to consume and even produce HTML5, I'm just not sure how thorough those capabilities are or whether they're based on any formal or informal standards. (Maybe the W3C has/had something like that, as part of it's attempts to rollup HTML5 snapshots into versioned standards?)
I lost any enthusiasm for XML after my experience with WDDX and XML-RPC, but as a foundation for HTML it was the best thing going. And maybe still is, given the absence of cross-toolchain contenders? Ditto for XSLT, at least if disregarding the choice to make the syntax homoiconic. In fact I circled back to XSLT long after it was clear it was a dead end. A good tool is a good tool, and the fact it remains so despite the wanton neglect only proves it.
> HTML5 could have taken the extra step of defining a canonical XML or XML-compatible DOM encoding, or at least encouraged it.
Yeah and then we could have called it xhtml5. Too bad that does not exist. Oh wait https://html.spec.whatwg.org/multipage/xhtml.html
> But the anti-XML sentiment was explicit and spiteful.
No, xhtml was just a bad idea creating tons of problems and solving none.
> xhtml was just a bad idea creating tons of problems and solving none.
Well an XHTML parser (and serializer) is a lot simpler, which is a pretty meaningful problem to solve.
What problems does xhtml create?
The main one is that even a slightly broken XHTML document will fail to render. HTML is much more forgiving.
I'm curious, what exactly in the DOM is not XML-compatible?
i think xhtml happened before the wider world of web devs were ready for it. Component based architectures took longer to be adopted than I certainly expected.
It might actually work if reintroduced these days as long as we can consider many components to be valid documents.
And the rendering was very slow back at the day.
The XSLT 1.0 spec specifically was written pretty badly, though, to my recollection; I had a hard time at making sense of it
Yeah, XSLT 1.0 has some really obvious missteps, so much so that to my knowledge basically nobody just implements XSLT 1.0. What they actually support is (most of) XSLT 1.0 plus a handful of EXSLT extensions (which are completely unofficial and not part of any XSLT spec, by the way). In my opinion the EXSLT stuff is the bare minimum needed to make XSLT 1.0 at least a passable language. Meanwhile, the XSLT spec evolved into 2.0 and 3.0, which as far as I'm aware, even to this day, has no complete open-source implementation.
i just got flashbacks to a past life where i handcrafted XSLT to pre-render output from a service as HTML server side. Of course the front end was running some asp.net version and Microsoft flavored XSLT had lots of quirks.
In the age of LLMs I would expect that legacy code bet carried indefinitely. The LLMs will have it indefinitely in their training data, and with code "cheap" to produce now, what are the good reasons for dropping legacy code?
The obvious answer is that LLMs are not quite the machine gods they're marketed as, innit.
The breakage that sticks out to me is that IIS in Windows Server outputs some reports as XML+XSLT and these have become nigh unusable for years now.
I ignore every official statement about “support” and simply look at the horse's mouth: Microsoft hasn’t bothered to fix this in IIS, and likely never will.
It’s a dead product, “supported” only in a contractual sense, not a practical one.
(If you called support right now demanding fix for this, they’d tell you that it’s broken by design, have you tried moving to a recurring revenue service offering?)
https://web.archive.org/web/20261017201132/https://doctor-se... while it gives 503
There's a long discussion about XSLT removal here: https://github.com/whatwg/html/issues/11578#issuecomment-595... (the link is to the comment with this proposal https://github.com/doriantaylor/swet which already is much better than any templating proposal "the platform" is trying to push)
Edge is Chrome.
503
So, this site breaks, we know that much
doctor-seo dot net has failed us. What is this world coming to?
Looks like the site broke
It is wild to look back at XHTML and see that the W3C were entirely correct about XML. They envisaged a world of schemas, client side templating, custom elements, dynamic forms, the works.
Alas, for laughably bad reasons we had to scrap all that for HTML5, Javascript and CSS; a stack so awful that most devs doing anything on the frontend immediately scramble to React, TypeScript, Tailwind, whatever it takes to avoid the underlying garbage.
A horrid state of affairs that will only get worse as time goes on.
They were wrong about one thing: tooling matters.
The XHTML/XML/XSLT tooling was bad, and XSLT was hard to reason about. That meant that amateurs had no way to learn it, and those amateurs went to school and became the workforce.
The web became a winner because it was easy to get something working. And then Google made it a mission to make great developer tools in everyone's hands for free.
I think in 2026 we could build the tooling around a better experience, but it would require thinking about the developer experience first.
You could do some awesome things with XML/XSL. My favorite was RSS feeds or OPML collections of RSS feeds (both flavors of XML) calling an XSL transformation when viewed in a web browser instead of mined by computers for data; same with TEI files, although that was a bit more arcane. The idea was that you'd have one data file for machine use and a way to present that data to humans as a web page.
But, as a stack, the XML/XSL/XPath/etc combination was weak because XSLT was hard to comprehend and never updated. No browser supports XSLT 2 or 3; they froze support with 1. XSLT 2 was 2007, a year before HTML 5 was a thing, yet it never got picked up by browsers. Javascript was just easier to understand than XSLT. Development of XHTML was also glacial, and people wanted new tags, especially for video.
I can't help but agree, and sometimes I think about the alternate version of the web where XML realized its full potential as the dominant technology. The obvious problem with XML is that the syntax is so verbose and redundant that it's only barely human-writable, but this is 100% a solvable problem.
yet people will say that HTML5 is all you need or something