I want browsers to support XSLT 2.0 and later versions

I want browsers to support XSLT 2.0 and 3.0 — not just the XSLT 1.0 specification that has been frozen in browser implementations for decades.

Every major browser currently ships an XSLTProcessor that is capped at XSLT 1.0, which was published in 1999. XSLT 2.0 brought significant improvements — including support for multiple output documents, grouping instructions (xsl:for-each-group), regular expressions, date and time functions, and a far richer type system based on XML Schema. XSLT 3.0 adds streaming transformations, higher-order functions, and JSON support, making it genuinely useful for modern data-processing tasks on the web.

Without native browser support, developers who need XSLT 2.0 or 3.0 functionality must either ship a large JavaScript polyfill (such as Saxon-JS) or pre-process XML server-side, adding overhead and limiting the dynamic, client-side transformation use cases that the XSLTProcessor API was designed to enable.

Expanding browser XSLT support would benefit anyone working with XML-based data formats — including SVG pipelines, publishing workflows, government and enterprise data interchange, and academic or standards-body documents — without requiring them to bundle a megabyte of JavaScript to compensate for a gap that the platform itself could close.