EXTRA BITS: SGML HTML XML - Computerphile

TL;DR

XML was developed as a subset of SGML, enabling structured and standardized data on the web, leading to the creation of cleaned up versions of HTML and various other tag sets.

Transcript

we've been wandering down the the buy roads of html x ml sgml all sorts of mls and various non-mls and last time i think we spoke some people had wandered off to the pub and sorted everything out over a pint so what happened about that then what happened next well after about 18 months the draft xml specification was published and everybody agreed ... Read More

Key Insights

• 🥺 XML specification addressed issues faced with HTML, including the requirement to include end tags, leading to a more structured and standardized approach to web development.
• 😚 XML enabled browser implementers to perform validation operations, ensuring that all tags were properly closed and the structure of web pages was accurate.
• 😫 XML served as the foundation for the development of cleaned up versions of existing tag sets, such as XHTML, and the creation of new tag sets, including mathematics markup and scalable vector graphics.
• 😫 Tim Berners-Lee's move to MIT and the establishment of the W3C played a significant role in setting web standards and promoting vendor neutrality.

Questions & Answers

Q: What was the major difference between HTML and XML?

The major difference was that XML required the inclusion of end tags, while HTML allowed for the omission of end tags. This made XML more structured and standardized.

Q: Why do some web developers still not include end tags in XML?

Some web developers, especially those who hand code, may omit end tags in XML for convenience or lack of awareness. However, it is best practice to include end tags to ensure proper validation.

Q: How did XML benefit browser implementers?

XML allowed browser implementers to perform a brackets matching operation, ensuring that all tags in a web page were properly closed. This made it easier to validate the structure of web pages and detect any errors or inconsistencies.

Q: What role did the XML committee play in web development?

The XML committee was responsible for enabling XML as a proper subset of SGML, allowing for the creation of cleaned up versions of existing tag sets, such as HTML, and the development of new tag sets.

Summary & Key Takeaways

• The XML specification was published after 18 months, addressing the issues faced with HTML and introducing the requirement to include end tags in XML.

• XML enabled browsers to perform a brackets matching operation, ensuring that all tags were matched and validating the structure of web pages.

• XML served as the foundation for the development of cleaned up versions of HTML and the creation of numerous tag sets, including mathematics markup and scalable vector graphics.