A modern, spec-compliant XML platform native to .NET Core.
XSLT, XQuery and XPath implemented directly in .NET Core, with async throughout, and Apache-2.0.
XSLT stopped advancing in importance in the .NET ecosystem at version 1.0 and never moved past it. That ends with the Phoenixml XML platform. We not only bring XSLT up to speed with the latest specification, we also introduce XQuery (the XML Query language) and other standards-based components in the works.
These engines are conformance-tested against the W3C xslt30-test and qt3tests corpora and run real production stylesheets. DocBook xslTNG is among a small but growing list.
The documentation covers the language surface and how to use them, as do the XSLT and XQuery MCP servers, so you can train your AI to build document-driven solutions faster.
| You want to | Go here |
|---|---|
| Transform or query from the command line | phoenixmldb-cli - dotnet tool install -g xslt |
| Use the engines from your own code | phoenixmldb-xslt · phoenixmldb-xquery |
| Give your coding agent XML expertise | xslt-mcp · xquery-mcp |
| Test your stylesheets from the command line | phxspec - XSpec on .NET Core |
| Read the documentation on XSLT, XQuery, and our tools | phoenixml.dev |
| Understand the platform and see where it's going | phoenixml.net · roadmap |
phoenixmldb-xslt implements XSLT, with
streaming, higher-order functions, maps, arrays and JSON support.
phoenixmldb-xquery implements XQuery and
XPath, with FLWOR expressions, window clauses, full-text search and the Update Facility, allowing for updating datasets from the query language. Did we mention JSON support?
phoenixmldb-core holds the XDM node model
and the shared primitives both engines build on.
phoenixmldb-cli ships the xslt and
xquery4 global tools for transforms, queries and batch processing.
xslt-mcp and
xquery-mcp are MCP servers that give a coding
agent spec lookup, validation and execution, each shipping a reference corpus drawn from the
specifications. Available as .NET tools or self-contained binaries.
xspec is our fork of
XSpec, the BDD test framework for XSLT, XQuery and Schematron
created by Jeni Tennison, running on .NET as a first-class addition to existing JVM and Saxon support.
crucible is a static site generator that converts
Markdown to XML to XSLT to HTML, built on the engines above. Built loosely around the JetBrains Writerside, Crucible supports the addition of .NET library documentation as well as Analytics, Mermaid, Javascript and other features to build out a modern, user-friendly documentation experience.
No problem. Open an issue on the repo where you're having trouble and we'll take a look. See CONTRIBUTING for details.