Pluralization now handles edge cases (NA, NaN, Inf and -Inf)
better (@rundel, #716).

The URI generated for .file, .run, .help and .vignette hyperlinks
can now be configured via options and env vars (@jennybc, #739, #744).

cli_progress_bar() now accepts total = Inf or -Inf which mimics the
behavior of when total is NA (@LouisMPenrod, #630).

num_ansi_colors() now does not warn in Emacs if the INSIDE_EMACS
environment variable is not a proper version number (@rundel, #689).

ansi_collapse() and inline collapsing now uses last as the separator
(without the serial comma) for two-element vectors if sep2 is not
given (@rundel, #681).

ansi_collapse() is now correct for length-1 vectors with style "head"
if width is specified (@rundel, #590).

New hash_xxhash() etc. functions to calculate the xxHash of strings,
raw vectors, objects, files.

cli now builds on ARM Windows.

"Solarized Dark" is now the default syntax highlighting theme in
terminals.

The {.obj_type_friendly} inline style now only shows the first class
name (#669 @olivroy).

Syntax highlighting now does not fail in RStudio if the rstudioapi
package is not installed (#697).

ansi_collapse(x, trunc = 1, style = "head") now indeed shows one
element if length(x) == 2, as documented (@salim-b, #572).

ansi_collapse() gains a sep2 argument to specify a seperate separator
for length-two inputs. It defaults to " and " which, in conjunction with
the other defaults, produces a collapsed string that fully adheres to the
serial comma rules.
(@salim-b, #569)

ansi_string() is now an exported function (@multimeric, #573).

The progressr progress handler now reports progress correctly
(@HenrikBengtsson, #558).

New hash_*sha1() functions to calculate the SHA-1 hash of strings,
objects, files.

cli now shows progress bars after one second by default, if they
are less than half way at the point. (Or after two seconds,
unconditionally, as before.) See the the cli.progress_show_after
option in ?cli-config for details (#542).

format_inline() now has a new argument keep_whitespace, and it keeps
whitespace, including newline and form feed characters by default.

New keypress() function to read a single key press from a terminal.

New function pretty_print_code() to print function objects with syntax
highlighting at the R console.

col_* and bg_* functions how handle zero-length input correctly (#532).

New function ansi_collapse() to collapse character vectors into a single
string.

ansi_strtrim() now handles some edge cases better, when ellipsis has
length zero, and when it is wider than width.

New hash_file_md5() function to calculate the MD5 hash of one or more
files.

cli has better error messages now.

New format_inline() argument: collapse, to collapse multi-line output,
potentially because of \f characters.

New experimental styles to create ANSI hyperlinks in RStudio and
terminals that support them. See ?cli::links for details (#513).

Expressions that start and end with a {} substitution are now styled
correctly. E.g. {.code {var1} + {var2}} (#517).

New {.obj_type_friendly} inline style to format the type of an R object
in a user friendly way (#463).

Improved vector collapsing behavior. cli now shows both the beginning
and end of the collapsed vector, by default (#419).

Nested cli() calls work now (#497).

Return values now work as they should within cli() calls (#496).

Style attributes with underscores have new names with dashes instead:
vec_sep, vec_last, vec_trunc, string-quote. The old names still
work, but the new ones take precedence (#483).

cli now does not crash at the end of the R session on Arm Windows
(#494; @kevinushey)

Vectors are truncated at 20 elements now by default, instead of 100 (#430).

20 new spinners from the awesome
cli-spinners package,
and from @HenrikBengtsson in #469.
Run this to demo them, some need UTF-8 and emoji support:

new <- c("dots13", "dots8Bit", "sand", "material", "weather", "christmas",
  "grenade", "point", "layer", "betaWave", "fingerDance", "fistBump",
  "soccerHeader", "mindblown", "speaker", "orangePulse", "bluePulse",
  "orangeBluePulse", "timeTravel", "aesthetic", "growVeriticalDotsLR",
  "growVeriticalDotsRL", "growVeriticalDotsLL", "growVeriticalDotsRR")
demo_spinners(new)

cli exit handlers are now compatible again with the withr package (#437).

cli functions now keep trailing \f characters as newlines.
They also keep multiple consecutive \f as multiple newlinees (#491).

{} substitutions within inline styles are now formatted correctly.
E.g. {.code download({url})} will not add backticks to url, and
{.val pre-{x}-post} will format the whole value instead of x.
(#422, #474).

cli now replaces newline characters within {.class ... } inline styles
with spaces. If the cli.warn_inline_newlines option is set to TRUE, then
it also throws a warning. (#417).

code_highlight now falls back to the default theme (instead of no theme)
for unknown RStudio themes (#482, @rossellhayes).

cli_abort() now supplies .frame to abort(). This fixes an
issue with the .internal = TRUE argument (r-lib/rlang#1386).

cli now does a better job at detecting the RStudio build pane, job pane
and render pane, and their capabilities w.r.t. ANSI colors and hyperlinks.
Note that this requires a daily build of RStudio (#465).

New functions for ANSI strings: ansi_grep(), ansi_grepl(),
ansi_nzchar(). They work like the corresponding base R functions, but
handle ANSI markup.

style_hyperlink() (really) no longer breaks if the env variable VTE_VERSION
is of the form \d{4}, i.e., 4 consecutive numbers (#441, @MichaelChirico)

cli_dl() and its corresponding cli_li() can now style the labels.

The behavior cli's inline styling expressions is now more predictable.
cli does not try to evaluate a styled string as an R expression any more.
E.g. the meaning of "{.emph +1}" is now always the "+1", with style
.emph, even if an .emph variable is available and the .emph + 1
expression can be evaluated.

Functions that apply bright background colors (e.g. bg_br_yellow()) now
close themselves. They no longer format text after the end of the function
(#484, @rossellhayes).

style_hyperlink() no longer breaks if the env varible VTE_VERSION
is of the form \d{4}, i.e., 4 consecutive numbers (#441, @MichaelChirico)

ansi_*() functions support ANSI hyperlinks again (#444).

Turning off ANSI colors via the cli.num_colors option or the
R_CLI_NUM_COLORS or the NO_COLOR environment variable now also turns off
ANSI hyperlinks (#447).

symbol now only has two variants: UTF-8 and ASCII. There are no special
variants for RStudio and Windows RGui any more (#424).