XML
The Extensible Markup Language (XML) is a general-purpose specification for creating custom markup languages.[1] It is classified as an extensible language because it allows its users to define their own elements. Its primary purpose is to facilitate the sharing of structured data across different information systems, particularly via the Internet,[2] and it is used both to encode documents and to serilize data. In the latter context, it is comparable with other text-based serialization languages such as JSON and YAML
XML > TOOLS
Apache XML Project - XML parsers, XSL-T processors and XML processing frameworks.
http://xml.apache.org/
Free XML Tools and Software - Categorized listing of software available for download. Categories include control information development (creating, modifying and documenting DTDs and XSL style sheets), conversion, storage and management, editing and composition, delivery, parsers and engines.
http://www.garshol.priv.no/download/xmltools/
Oracle XML Developer's Kit - Parsers, schema processors, and class generators for Java, C, C++ and PL/SQL.
http://www.oracle.com/technology/tech/xml/index.html
RustemSoft - Utilities for conversion to XML from various formats including MS Office, SQL Server, Oracle, ODBC format and text source formats.
http://rustemsoft.com/
Webreference.com: XML tools - A collection of GNU software tools for processing XML and its derivates, such as RSS.
http://www.webreference.com/xml/tools/