Join MDN and developers like you at Mozilla's View Source conference, 12-14 September in Berlin, Germany. Learn more at

The Standard Generalized Markup Language (SGML) is an ISO specification made for defining declarative markup languages.

On the web, HTML 4, XHTML, and XML are popular SGML-based languages. It is worth noting that since its fifth edition, HTML is no longer SGML-based and has its own parsing rules.

Learn more

Document Tags and Contributors

 Contributors to this page: hbloomer, andy1633, Jeremie, Andrew_Pfeiffer, klez, Biraj, teoli, avsaro
 Last updated by: hbloomer,