Language Reference

XPath, XSLT, and XQuery documentation for .NET developers

#Language Reference

Comprehensive documentation for the XML technology stack — XPath, XSLT, and XQuery — written for .NET developers who work with data integration.

If you've spent your career working with JSON and REST APIs, you might wonder why XML technologies still matter. XML remains the backbone of enterprise data exchange, document processing, healthcare (HL7/FHIR), financial services (FpML, SWIFT), government standards, and publishing. When you need to transform, query, or validate structured documents at scale, XPath, XSLT, and XQuery are purpose-built tools that no amount of System.Text.Json will replace.

#Where to Start

If you know...

Then you'll appreciate...

LINQ to XML

XPath — same idea, standardized syntax

Razor / Handlebars

XSLT — declarative template-based transforms

SQL

XQuery — query language for hierarchical data

jq for JSON

XPath/XQuery — the XML equivalents, with more power

  • XML Foundations — If you're new to XML or need a refresher, start here.

  • XPath — The query language for XML.

  • XSLT — Transform XML documents into HTML, JSON, CSV, or plain text.

  • XQuery — A full programming language for querying and constructing XML.

  • XInclude — Assemble one XML document out of several source files.

  • XPointer — Select a fragment of a target document for XInclude to pull in.