Editing XSLT (section)

==Processor implementations==
*RaptorXML from [[Altova]] is an XSLT 3.0 processor available in the XMLSpy development toolkit and as a free-standing server implementation, invoked using a REST interface.
*[[IBM]] offers XSLT processing embedded in a special-purpose hardware appliance under the [[IBM WebSphere DataPower SOA Appliances|Datapower]] brand.
*[[libxslt]] is a [[free software|free]] [[library (computing)|library]] released under the [[MIT License]] that can be reused in commercial applications. It is based on [[libxml]] and implemented in [[C (programming language)|C]] for speed and portability. It supports XSLT 1.0 and [[EXSLT]] extensions.<ref>{{cite web|title=The XSLT C library for GNOME: libxslt|url=http://xmlsoft.org/XSLT/index.html|access-date=23 November 2012}}</ref>
**It can be used at the command line via xsltproc<ref>{{cite web|title=The XSLT C library for GNOME: The xsltproc tool|url=http://xmlsoft.org/XSLT/xsltproc2.html|access-date=23 November 2012}}</ref> which is included in [[macOS]]<ref>{{cite web|title=xsltproc man page|url=https://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man1/xsltproc.1.html|access-date=23 November 2012}}</ref> and many [[Linux distributions]], and can be used on [[Microsoft Windows|Windows]] via [[Cygwin]].<ref>{{cite web|title=New package: libxslt|url=http://www.cygwin.com/ml/cygwin-announce/2002/msg00018.html|access-date=23 November 2012}}</ref>
**The [[WebKit]] and [[Blink (layout engine)|Blink]] layout engines, used for example in the [[Apple Safari|Safari]] and [[Google Chrome|Chrome]] web browsers respectively, uses the libxslt library to do XSL transformations.<ref>{{cite web | url=http://webkit.org/projects/xslt/index.html | title=The WebKit Open Source Project – XSLT | access-date=2009-10-25}}</ref>
**[[Language binding|Bindings]] exist for [[Python (programming language)|Python]],<ref>{{cite web|title=The XML C parser and toolkit of Gnome: Python and bindings|url=http://xmlsoft.org/python.html|access-date=23 November 2012}}</ref> [[Perl]],<ref>{{cite web|title=XML::LibXSLT – Interface to the GNOME libxslt library|url=https://metacpan.org/module/XML::LibXSLT|publisher=CPAN|access-date=23 November 2012}}</ref> [[Ruby (programming language)|Ruby]],<ref>{{cite web|title=libxslt-ruby|url=http://rubygems.org/gems/libxslt-ruby|access-date=23 November 2012}}</ref> [[PHP]],<ref>{{cite web|title=libxml|url=http://www.php.net/manual/en/book.libxml.php|access-date=23 November 2012}}</ref> [[Common Lisp]],<ref>{{cite web|title=cl-libxml2 High-level wrapper around libxml2 and libxslt libraries |url=https://code.google.com/p/cl-libxml2/}}</ref> [[Tcl]],<ref>{{cite web|title=TclXML|url=http://tclxml.sourceforge.net/|access-date=21 May 2013}}</ref> and [[C++]].<ref>{{cite web|title=libxml++|url=http://libxmlplusplus.sourceforge.net/|publisher=sourceforge.net|access-date=23 November 2012}}</ref>
*[[Microsoft]] provides two XSLT processors (both XSLT 1.0 only). The earlier processor [[MSXML]] provides COM interfaces; from MSXML 4.0 it also includes the command line utility <code>msxsl.exe</code>.<ref>{{cite web|title=Command Line Transformation Utility (msxsl.exe)|url=http://www.microsoft.com/en-us/download/details.aspx?id=21714|publisher=Microsoft|access-date=22 October 2012}}</ref> The .NET runtime includes a separate built-in XSLT processor in its <code>System.Xml.Xsl</code> library.
*[[Saxon XSLT|Saxon]] is an XSLT 3.0 and XQuery 3.1 processor with [[open-source software|open-source]] and [[proprietary software|proprietary]] versions for stand-alone operation and for [[Java (programming language)|Java]], [[JavaScript]] and .NET. A separate product Saxon-JS<ref>{{cite web|title=Saxon-JS|url=http://www.saxonica.com/saxon-js/index.xml|publisher=Saxonica|access-date=6 September 2018}}</ref> offers XSLT 3.0 processing on [[Node.js]] and in the browser.
*[https://github.com/egh/xjslt xjslt] is an [[open-source software|open-source]] XSLT 2.0 compiler for [[JavaScript]] supporting [[Node.js]] and the browser.
*[[Xalan]] is an open source XSLT 1.0 processor from the [[Apache Software Foundation]] available for Java and C++. A variant of the Xalan processor is included as the default XSLT processor in the standard Java distribution from Oracle.
*Web browsers: Safari, Chrome, Firefox, Opera and Internet Explorer all support XSLT 1.0 (only).<ref>{{cite web |title=Common XSLT Errors |url=https://developer.mozilla.org/en-US/docs/Web/XSLT/Common_errors |website=MDN Web Docs |publisher=Mozilla |access-date=16 September 2024 |date=10 July 2023}}</ref> Browsers can perform on-the-fly transformations of XML files and display the transformation output in the browser window. This is done either by embedding the XSL in the XML document or by referencing a file containing XSL instructions from the XML document. The latter may not work with Chrome on files from local filesystem because of its security model.<ref>{{cite web |url= https://bugs.chromium.org/p/chromium/issues/detail?id=58151 |title=Issue 58151: Fails to load xml file on local file system using XMLHttpRequest }}</ref>
*Adobe AXSLE engine, a proprietary library

===Performance===
Most early XSLT processors were interpreters.  More recently, code generation is increasingly common, using portable intermediate languages (such as [[Java bytecode]] or .NET [[Common Intermediate Language]]) as the target. However, even the interpretive products generally offer separate analysis and execution phases, allowing an optimized expression tree to be created in memory and reused to perform multiple transformations. This gives substantial performance benefits in online publishing applications, where the same transformation is applied many times per second to different source documents.<ref>[http://www-128.ibm.com/developerworks/xml/library/x-xslt2/ Saxon: Anatomy of an XSLT processor] – Article describing implementation &amp; optimization details of a popular XSLT processor.</ref> This separation is reflected in the design of XSLT processing APIs (such as [[Java API for XML Processing|JAXP]]).

Early XSLT processors had very few optimizations.  Stylesheet documents were read into [[Document Object Model]]s and the processor would act on them directly. [[XPath]] engines were also not optimized. Increasingly, however, XSLT processors use optimization techniques found in functional programming languages and database query languages, such as static rewriting of an expression tree (e.g., to move calculations out of loops), and lazy pipelined evaluation to reduce the [[memory footprint]] of intermediate results (and allow "early exit" when the processor can evaluate an expression such as <code>following-sibling::*[1]</code> without a complete evaluation of all subexpressions). Many processors also use tree representations that are significantly more efficient (in both space and time)<ref>{{Cite journal|title=Improving Pattern Matching Performance in XSLT|first1=John|last1=Lumley|first2=Michael|last2=Kay|date=June 2015|journal=XML London 2015|doi=10.14337/XMLLondon15.Lumley01|url=http://xmllondon.com/2015/presentations/lumley|pages=9–25|doi-broken-date=1 November 2024 |isbn=978-0-9926471-2-4|doi-access=free}}</ref> than general-purpose DOM implementations.

In June 2014, Debbie Lockett and [[Michael Howard Kay|Michael Kay]] introduced an open-source benchmarking framework for XSLT processors called XT-Speedo.<ref>{{Cite journal|title=Benchmarking XSLT Performance|first1=Michael|last1=Kay|first2=Debbie|last2=Lockett|date=June 2014|journal=XML London 2014|doi=10.14337/XMLLondon14.Kay01|url=http://xmllondon.com/2014/presentations/kay|pages=10–23|doi-broken-date=1 November 2024 |isbn=978-0-9926471-1-7|doi-access=free}}</ref>