and XQuery 3.1 functionality, as defined by the respective specifications. In addition, Saxon-HE implements certain features that the XSLT 3.0 specification declares as optional and that were previously reserved for the commercial versions, such as dynamic XPath 3.1 evaluation and higher-order functions in XSLT 3.0. The commercial versions are called Saxon-PE and Saxon-EE. A detailed and up-to-date feature matrix can be found on the Saxonica web site. The fourth technology platform is JavaScript. Previously the open-source XSLT processor Saxon-CE was cross-compiled from the common Java source using GWT. SaxonJS is a completely new implementation in JavaScript. The XSLT sources can either be compiled using Saxon-EE or using a built-in XSLT-based XSLT compiler, which creates less optimized code. On the other hand, the XSLT-based XSLT compiler allows dynamic compilation and execution of XSLT. While SaxonJS supports most of the XSLT 3.0 and XPath 3.1 features available in Saxon-HE, SaxonJS does not support XQuery. In contrast to Saxon-HE and the discontinued Saxon-CE, SaxonJS is not open source, but it can be used for free in the browser or in Node.js. See also libxml2/Libxslt (competitor) Xalan (competitor) References External links Saxon-B homepage Saxonica homepage, for Saxon-SA Saxon XQuery Tools AntillesXML (GUI for Saxon) description of Saxon (German) Free system software Java platform XQuery processors XSLT processors