[ultraism]

Don't use plaintext, use LaTeX. Since paragraphs are separated by an empty line, you can have each sentence on a separate in a paragraph on a separate line and have it still formatted as a paragraph in the final document. This allows for better diffs. Here is an example:

https://github.com/dart-lang/language/blob/master/specificat...

[dragonwriter]

> Don't use plaintext, use LaTeX

Markdown or Asciidoc has the same benefit as far as paragraphs.

[ultraism]

Markdown doesn't address table of contents or references which were mentioned above.

[dragonwriter]

Asciidoc does, and there are TOC tools for markdown, though they are add-ons to markdown processors.