An XML parser is a software component that can read an XML document and pass the data in it to an application.
An XSLT processor is basically an XML application, which requires an underlying XML parser. The XSLT processor applies an XSL file (an Extensible Stylesheet Language file) to an XML file of a certain grammar and transforms it to a different XML grammar or a non XML format.
JAXP 1.3 (J2SE 1.5) reference implementation is, Parser Xerces J, stylesheet processor Xalan J. Check
here [ October 13, 2008: Message edited by: Gamini Sirisena ]