Talk:IBM Generalized Markup Language

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HTML and XML aren't really applications of SGML. HTML started life as it's own format which happened to use pointy brackets. SGML was retrofitted to HTML - later standardised versions had an SGML DTD associated to them. However I suspect a minute percentage of HTML pages at any point in time were ever valid and compatible with an SGML parser.

Saying XML is an application of SGML is completely wrong. XML has its roots in SGML, but it is not an application of it.

SGML is a system for creating application specific data formats - each of these uses is an 'application'. Ditto XML is a system for creating application specific data formats, and has it's applications.

XML was created to be "SGML for the web". It introduced backward incompatible changes - DTDs were optional, introduced the empty tag syntax, it supported Unicode etc. At the point of its creation, XML was not a subset of SGML - some well formed or even valid XML files were not compatible with SGML. This is not a flaw, XML set out to be a different standard.

Later on, the SGML standard was extended so that XML files could be considered a subset of SGML documents, but that is a recent development in the history of SGML. —Preceding unsigned comment added by 83.70.240.232 (talk • contribs) 12 October 2005

[edit] one of two

GML preceded and was one of the two sources that were used as the basis for the industry-developed Standard Generalized Markup Language (SGML)

There's a statement that GML was "one of two" influences on SGML, but you don't list the other one; I think you mean the whole RUNOFF inspired line of markup. —Preceding unsigned comment added by 71.156.15.166 (talk • contribs) 22 June 2006

I too would like to know what the other one is. I dont think it can be RUNOFF, as it doesnt appear to be a metalanguage. Jayvdb 07:45, 27 September 2006 (UTC)

[edit] re: example and influence on HTML

The example given shows GML in its default, out-of-the-box configuration. At our installation circa 1986 (and I'm pretty sure this was common) we replaced the start and end delimiters with < and > to give markup that looked like this:

   <h1>Chapter 1:  Introduction
   <p>GML supported hierarchical containers, such as
   <ol>
   <li>Ordered lists (like this one),
   <li>Unordered lists, and
   <li>Definition lists
   <eol>
   as well as simple structures.
   <p>Markup minimization (later generalized and formalized in SGML),
   allowed the end-tags to be omitted for the "h1" and "p" elements.

which starts to look a lot more like a direct influence on HTML. GML also had the table tag, the a tag with xref, etc. 91.125.101.51 (talk) 09:29, 30 November 2007 (UTC)

Yes, many of the original HTML tags were taken directly from the GML starter set (which, of course, was in use at CERN at the time). A particularly good 'example' is the <xmp> tag, which is taken directly from the GML :xmp. tag name – which is spelled without the leading 'e' because the 'e' is reserved to indicate end-tags in the GML default syntax. mfc 20:28, 30 November 2007 (UTC)