Abstract: The Earth Science Markup Language (ESML) is a specialized markup
language for Earth Science metadata based on the eXtensible Markup
Language (XML?). It is designed to provide a standard way for
describing content, structure and semantic information of a data file,
thus facilitating development of dataset-independent search,
visualization, and analysis tools without requiring data to be in any
... particular format or formats.

Why write an ESML file:

The ESML, is a means for describing the content, structure and
semantic information about different Earth Science data
formats. Content metadata describes the contents of a file in
human-readable terms. In ESML, content metadata for Earth Science data
products is based on the Federal Geographic Data Committee, Global
Change Master Directory, the EOSDIS Core System, and others. Syntactic
metadata describe the structure of the file in machine-readable
terms. HDF-EOS and HDF provide this mechanism for HDF-EOS files. ESML
would rely on existing standard formats, such as HDF and HDF-EOS, to
provide the syntactic metadata when available, but would also provide
facilities to define these metadata for file formats that are not
self-describing, such as ASCII or simple binary files. The third type
of information is semantic metadata, which describe the contents of a
file in machine-readable terms such that an application can interpret
the data in an intelligent manner. ESML will provide this crucial
information. With ESML you will now be able to write your data in any
of your favorite data formats and instead of writing a README file for
users, you can provide an ESML file. This file is not only human
readable but is also machine readable and interpretable. Any
application that can parse an ESML file will now be able to read the
data file regardless of its format. As a bonus, the user can also
publish the ESML on the web. This allows other users to utilize web
search engines to find data of interest.