XML---an opportunity for meaningful data standards in the geosciences

Abstract Extensible markup language (XML) is a recently introduced meta-language standard on the Web. It provides the rules for development of metadata (markup) standards for information transfer in specific fields. XML allows development of markup languages that describe what information is rather than how it should be presented. This allows computer applications to process the information in intelligent ways. In contrast hypertext markup language (HTML), which fuelled the initial growth of the Web, is a metadata standard concerned exclusively with presentation of information. Besides its potential for revolutionizing Web activities, XML provides an opportunity for development of meaningful data standards in specific application fields. The rapid endorsement of XML by science, industry and e-commerce has already spawned new metadata standards in such fields as mathematics, chemistry, astronomy, multi-media and Web micro-payments. Development of XML-based data standards in the geosciences would significantly reduce the effort currently wasted on manipulating and reformatting data between different computer platforms and applications and would ensure compatibility with the new generation of Web browsers. This paper explores the evolution, benefits and status of XML and related standards in the more general context of Web activities and uses this as a platform for discussion of its potential for development of data standards in the geosciences. Some of the advantages of XML are illustrated by a simple, browser-compatible demonstration of XML functionality applied to a borehole log dataset. The XML dataset and the associated stylesheet and schema declarations are available for FTP download.