Markup Notes

Forms of Documentation Markup

In the past, many solutions have evolved to facilitate the easy creation of documents and documentation. These range from lightweight human-readable formats like Markdown, to highly capable typesetting systems like TeX/LaTeX, to structured data formats like XML. The choice of markup language typically reflects a trade-off between ease of authoring, rendering fidelity, and the intended output medium.

---++ Historical Background

The concept of "markup" predates computers — editors and typesetters would literally mark up manuscripts with instructions for printers. With the arrival of electronic publishing in the 1960s and 70s, these conventions were formalised into machine-readable languages. Early systems were tightly coupled to specific hardware (typesetters, printers, terminals), and over time higher-level, more portable formats emerged.

---++ Markup Languages and Formats

---+++ Runoff / Roff Family (1964 onwards) The roff family traces its roots to the =RUNOFF= program written by Jerome Saltzer at MIT in 1964. It was the dominant document formatting system on early UNIX systems.

  * *nroff* — formats text for fixed-width terminal output
  * *troff* — the typesetting variant, targeting phototypesetting devices
  * *groff* (GNU roff) — the modern open source successor, still widely used today for Unix man pages

Roff documents use dot-prefixed commands (e.g. =.PP= for paragraph, =.B= for bold) and remain the standard format for Linux/Unix manual pages.

---+++ SGML — Standard Generalised Markup Language (1986) SGML is a meta-language for defining markup languages, standardised as ISO 8879:1986. It introduced the concept of separating document structure from presentation, and was the parent of both HTML and XML. Its complexity limited widespread adoption outside publishing and aerospace/defence industries, but its influence is enormous.

---+++ TeX and LaTeX (1978 / 1984) Created by Donald Knuth, *TeX* is a typesetting system renowned for its precise, beautiful rendering of mathematical and scientific notation. *LaTeX*, built on top of TeX by Leslie Lamport, added higher-level macros that made document authoring far more approachable. LaTeX remains the dominant format for academic papers, theses, and scientific publishing worldwide. Documents use commands such as =\section{}=, =\textbf{}=, and the =equation= environment.

---+++ RTF — Rich Text Format (1987) Developed by Microsoft for cross-application and cross-platform document exchange. RTF encodes formatting as plain-text control words (e.g. =\b= for bold), making it human-readable in theory but verbose in practice. It was the default format for WordPad and early versions of Word, and served as a common interchange format before the dominance of OOXML and PDF.

---+++ HTML — HyperText Markup Language (1991)

Proposed by Tim Berners-Lee at CERN, HTML is an SGML-derived language that became the lingua franca of the World Wide Web. It separates document structure (tags like =