Apache Xalan Project is a collaborative software development project dedicated to providing robust, full-featured, commercial-quality, and freely available XSLT support on a wide variety of platforms.

Xalan-Java is an XSLT processor for transforming XML documents into
HTML, text, or other XML document types. It implements XSL Transformations (XSLT) Version 1.0 and
XML Path Language (XPath) Version 1.0 and can be used from the command line, in an applet or a
servlet, or as a module in other program.

Xalan-Java implements the javax.xml.transform interface in
Java API for XML Processing (JAXP) 1.3. This interface provides a modular
framework and a standard API for performing XML transformations, and utilizes system
properties to determine which Transformer and which XML parser to use.

Xalan-Java also implements the javax.xml.xpath interface in JAXP 1.3, which provides an
object-model neutral API for evaluation of XPath expressions and access to the evaluation
environment.