Xerces (named after the Xerces Blue butterfly) provides world-class XML parsing and generation. Fully-validating parsers are available for both Java and C++, implementing the W3C XML and DOM (Level 1 and 2) standards, as well as the de facto SAX (version 2) standard. The parsers are highly modular and configurable. Initial support for XML Schema (draft W3C standard) is also provided.

A Perl wrapper is provided for the C++ version of Xerces, which allows access to a fully validating DOM XML parser from Perl. It also provides for full access to Unicode strings, since Unicode is a key part of the XML standard.

A COM wrapper (also for Xerces-C) provides compatibility with the Microsoft MSXML parser.

Xalan (named after a rare musical instrument) provides high-performance XSLT stylesheet processing. Xalan fully implements the W3C XSLT and XPath recommendations. The stylesheet processor is feature-rich and robust. The XPath Processor is useable as a stand-alone unit. Xalan uses the Bean Scripting Framework (BSF) to implement Java or script extensions, features multiple document output extensions, and we are working on data-binding extensions for SQL/JDBC and other data providers.

Xalan is currently available in Java, and available in Alpha form for C++.

Cocoon is a powerful framework for XML web publishing which brings a whole new world of abstraction and ease to consolidated web site creation and management based on the XML paradigm and related technologies.

AxKit brings the power of XML web publishing and dynamic XML based applications to the Apache web server using the mod_perl framework and the Apache C API to combine the power of XML with the performance of a native Apache solution.

Forrest will be used for the creation and maintenance of the xml.apache.org website. It builds remote project documentation in Gump-like style, adds project metrics and offers a set of robust XML grammars for project documentation.

FOP is the world's first print formatter driven by XSL formatting objects. It is a Java 1.2 application that reads a formatting object tree and then turns it into a PDF document. The formatting object tree, can be in the form of an XML document (output by an XSLT engine like Xalan) or can be passed in memory as a DOM Document or (in the case of Xalan) SAX events.

Apache Xang lets you quickly build data-driven, cross-platform Web applications that integrate disparate data sources. The Xang architecture cleanly separates data, logic and presentation. It is based on open industry standards such as HTTP, XML, XSL, DOM and ECMAScript (JavaScript).

The Apache Soap project is an implementation of the draft W3C protocol by the same name. It is based on, and supersedes, the IBM SOAP4J implementation.

From the draft W3C specification: SOAP is a lightweight protocol for exchange of information in a decentralized, distributed environment. It is an XML based protocol that consists of three parts: an envelope that defines a framework for describing what is in a message and how to process it, a set of encoding rules for expressing instances of application-defined datatypes, and a convention for representing remote procedure calls and responses.

The source code for Crimson is available under the xml-crimson CVS module. Please visit the Crimson pages for more information.

Apache Xindice is a database designed from the ground up to store XML data or what is more commonly referred to as a native XML database.