This is a companion discussion topic for the original entry at https://www.rstudio.com/blog/announcing-the-r-markdown-book
It is exciting for us to see the amazing growth of the R Markdown ecosystem over the four years since the creation of R Markdown in 2014. Now you can author many types of documents, and build a wide range of applications based on R Markdown. As an effort to unite and improve the documentation of the R Markdown base package (rmarkdown) and several other extensions (such as bookdown, blogdown, pkgdown, flexdashboard, tufte, xaringan, rticles, and learnr) in one place, we authored a book titled “R Markdown: The Definitive Guide", which is to be published by Chapman & Hall/CRC in about two weeks.