[CryoLogic]

Most of the publishing industry still uses .docx, some of the more advanced publishers have moved over to ASCIIDoc - personally I think Markdown is the easiest to use for a big project (having written and published a technical book prior).

[floatboth]

Except for scientific publishing, where LaTeX is king.

[bjoli]

Most people I know use org mode with inline latex for stuff that needs to be latex.