ellipsis (>= 0.2.0), digest, glue, rlang (>= 0.4.5)

bit64, covr, crayon, generics, knitr, pillar (>= 1.4.1),
pkgdown, rmarkdown, testthat (>= 2.3.0), tibble, xml2, zeallot

Hadley Wickham [aut, cre],
  Lionel Henry [aut],
  Davis Vaughan [aut],
  RStudio [cph]

A rewrite of the graphics layout capabilities, plus some
  support for interaction.

A backend for the selecting functions of the 'tidyverse'.
    It makes it easy to implement select-like functions in your own
    packages in a way that is consistent with other 'tidyverse'
    interfaces for selection.

covr, crayon, dplyr, knitr, magrittr, rmarkdown, testthat (>=
2.3.0), tibble (>= 2.1.3), withr

person(given = "Kirill", family = "Müller", role = c("aut",
        "cre"), email = "krlmlr+r@mailbox.org")

Robust, reliable and flexible paths to files below a
    project root. The 'root' of a project is defined as a directory
    that matches a certain criterion, e.g., it contains a certain
    regular file.

testthat, mockr, knitr, withr, rmarkdown

'rrmake.R' 'criterion.R' 'file.R' 'has-file.R' 'root.R'
'rprojroot-package.R' 'shortcut.R' 'thisfile.R'

person("Jim", "Hester", email = "james.f.hester@gmail.com", role = c("aut", "cre"))

An implementation of interpreted string literals, inspired by
  Python's Literal String Interpolation <https://www.python.org/dev/peps/pep-0498/> and Docstrings
  <https://www.python.org/dev/peps/pep-0257/> and Julia's Triple-Quoted String Literals
  <https://docs.julialang.org/en/v1.3/manual/strings/#Triple-Quoted-String-Literals-1>.

testthat, covr, magrittr, crayon, knitr, rmarkdown, DBI,
RSQLite, R.utils, forcats, microbenchmark, rprintf, stringr,
ggplot2, dplyr, withr, vctrs (>= 0.2.2)

Encapsulated Classes with Reference Semantics

person("Winston", "Chang", role = c("aut", "cre"), email = "winston@stdout.org")

Creates classes with reference semantics, similar to R's built-in
    reference classes. Compared to reference classes, R6 classes are simpler
    and lighter-weight, and they are not built on S4 classes so they do not
    require the methods package. These classes allow public and private
    members, and they support inheritance, even when the classes are defined in
    different packages.