[edited Feb 27, 2019]
Preamble I released the first bookdown version of my Statistical Rethinking with brms, ggplot2, and the tidyverse project a couple weeks ago. I consider it the 0.9.0 version. I wanted a little time to step back from the project before giving it a final edit for the first major edition. I also wanted to give others a little time to take a look and suggest edits, which some thankfully have.
tl;dr I just self-published a book-length version of my project Statistical Rethinking with brms, ggplot2, and the tidyverse. By using Yihui Xie’s bookdown package, I was able to do it for free. If you’ve never heard of it, bookdown enables R users to write books and other long-form articles with R Markdown. You can save your bookdown products in a variety of formats (e.g., PDF, HTML) and publish them in several ways, too.