SAX2/Java Parsers and Drivers

The Apache XML Project's Xerces Java Parser
http://xml.apache.org/xerces-j/index.html
Sun's JAXP
http://java.sun.com/xml/
SAXON XSLT processor
http://users.iclway.co.uk/mhkay/saxon/
Oracle XML Developer's Kit for Java
http://technet.oracle.com/tech/xml/xdk_java.html
ParserAdapter
http://www.megginson.com/SAX/Java/index.html