Section 3.29 Slides
In addition to articles and books, support for authoring slideshows is also available, but is experimental (so tags and attributes are subject to change).
Currently, support for producing Reveal.js 1 and Beamer LaTeX 2 slideshows is available. Details on authoring may be found in Section 4.38, and publishing details are in Chapter 34.
Also, future support for annotating PreTeXt books and articles to export PreTeXt slides is in the works, but not yet available.