APIs and application support

• SAX is the Simple API for XML, a `common, event-based API for parsing XML documents'. See also the Oasis SAX links
• James Clark's XML pages include XP, a high-performance XML parser in Java (excellent), and XT, an implementation in Java of XSL Transformations (XSLT).
• XSL processors include: OpenXT - an open-source version of XT IBM's xml4j, Xalan - C++ XSLT processor.
• The Apache XML Project is a collection of free high-quality (well, they say `commercial-quality', but I presume they mean `high-quality') XML tools, including:
  • Xerxes - a set of validating XML parsers written in C++, Perl and Java
  • Xalan - XSLT stylesheet processors, in Java and C++
  • FOP - XSL-FO to PDF
• PassiveTeX processes XSL-FO (to DVI, PS, PDF, whatever your TeX system can produce), using the power of the TeX engine.
• The Oasis archive of public SGML/XML software, XML Tools. Lars Marius Garshol's Free XML tools and software.
• A rather nice-looking IBM tutorial on XML Programming in Java
• RXP - an XML parser available under the GPL, which can produce a serialisation of a document's infoset (from Richard Tobin)
• eXist is an Open Source native XML database
• Huge amounts more...