(See the sections on CSS and XSL below for more on formatting XML.) Separation of content and presentation is a key concept inherited from SGML. A lot of the programming is already done for you ...

Standard Generalized Markup Language (SGML) is a way of expressing data in text-processing applications. It's been around for more than a decade; both XML and HTML are document formats derived ...

Whereas HTML uses a fixed set of tags or codes to describe pages, XML maintains the flexible meta-language characteristics of SGML by defining the codes that will be used in each document.

Scholarly Digital Editions has released Anastasia, their next generation XML electronic publication system. Anastasia — which stands for Analytic System Tools and SGML/XML integration ...

Hypertext Markup Language (HTML) was the markup language used in a web browser; therefore, it started to be used widely.

Unlike SGML, the XML DTD was always optional, because the framers of XML knew there was enormous value in documents that were merely well-formed, even if not valid with respect to a DTD.