• Markup systems for annotating text for formatting and other purposes have existed since the 60's but most were Procedure Markup systems.

• Procedural Markup tells the application what to do with the information and not what the information represents.

• Motivation: "Procedural markup is also inflexible. If the user decides to change the style of his document (perhaps because he is using a different output device), he will need to repeat the markup process to reflect the changes." [1]

• The first "logical document model" system was Scribe (c. 1980) [2]

• Philosophy: Markup should be descriptive and describe the logical structure of the information (document) and not its particular use or format.

[1] http://www.sgmlsource.com/history/AnnexA.htm

[2] B. Reid, "Scribe: A Document Specification Language and its Compiler," Ph.D. Dissertation, Carnegie Mellon University, Pittsburgh, PA (October, 1980).