Markdown

Markdown has become the defacto method for much technical documentation. There are plenty of reasons to like Markdown.

• Easy to learn
• Easy to specify
• Broad general formatting support for text
• Significant addin support for specialized kinds of documentation
  • Mermaid Diagrams
  • MathJax for complex mathematical symbolism
  • LaTex also for math notation
  • HighlightJS for language highlighting

Although you can prepare Markdown with any text processor, you will probably need a Markdown editor to fully realize all of Markdown's possibilities. Two such editors are Markdown Monster and Documentation Monster which I personally find exceptionally useful. Both are paid products although you can download a trial version from their respective websites.

• Markdown Monster
• Documentation Monster