The following packages are needed by maintainers for using
'gnulib-tool'.  In general, Gnulib prefers the latest stable
version of each package, but in some cases it also supports
older versions; this caters to commonly-used software
distributions that may lag behind the latest stable package.
Support for older versions is not guaranteed, though, and
the version numbers in the following list may be incremented
at any time.

* A C runtime, compiler, linker, etc.
  + Mandatory. Using the platform's native 'cc' gives good portability
    exposure, but you can also use GCC 2.95 or newer.
  + GCC Homepage:
    https://gcc.gnu.org/
  + Download:
    https://ftp.gnu.org/gnu/gcc/

* A 'make' utility.
  + Mandatory. Using the platform's native 'make' gives good portability
    exposure for in-tree builds, but VPATH builds require GNU Make 3.79.1 or
    newer.
  + GNU Make Homepage:
    https://www.gnu.org/software/make/
  + Download:
    https://ftp.gnu.org/gnu/make/

* GNU M4 1.4.5 or newer.
  + 1.4.5 or newer is mandatory, but 1.4.9 or newer is recommended.
  + Homepage:
    https://www.gnu.org/software/m4/
  + Download:
    https://ftp.gnu.org/gnu/m4/

* Autoconf 2.63 or newer.
  + Mandatory.
  + Homepage:
    https://www.gnu.org/software/autoconf/
  + Download:
    https://ftp.gnu.org/gnu/autoconf/

* Automake 1.11.1 or newer.
  + Mandatory.
  + Homepage:
    https://www.gnu.org/software/automake/
  + Download:
    https://ftp.gnu.org/gnu/automake/

* A shell
  + Mandatory. Using the platform's native 'sh' gives good portability
    exposure, but you can also use Bash.
  + Homepage:
    https://www.gnu.org/software/bash/
  + Download:
    https://ftp.gnu.org/gnu/bash/

* Core POSIX utilities, including:
    [ basename cat chgrp chmod chown cp dd echo expand expr
    false hostname install kill ln ls md5sum mkdir mkfifo
    mknod mv printenv pwd rm rmdir sleep sort tee test touch
    true uname
  + Mandatory. Using the platform's native utilities gives good portability
    exposure, but you can also use GNU coreutils.
  + Homepage:
    https://www.gnu.org/software/coreutils/
  + Download:
    https://ftp.gnu.org/gnu/coreutils/

* The comparison utilities 'cmp' and 'diff'.
  + Mandatory. Using the platform's native utilities gives good portability
    exposure, but you can also use GNU diffutils.
  + Homepage:
    https://www.gnu.org/software/diffutils/
  + Download:
    https://ftp.gnu.org/gnu/diffutils/

* The patch utility 'patch'.
  + Mandatory if you use gnulib-local diffs. Using the platform's native
    utilities gives good portability exposure, but you can also use GNU
    patch.
  + Homepage:
    https://www.gnu.org/software/patch/
  + Download:
    https://ftp.gnu.org/gnu/patch/

* Grep.
  + Mandatory. Using the platform's native grep gives good portability
    exposure, but you can also use GNU grep.
  + Homepage:
    https://www.gnu.org/software/grep/
  + Download:
    https://ftp.gnu.org/gnu/grep/

* GNU gettext.
  + If your project wants to follow GNU Coding Standards:
    + Always use the newest available gettext release, see
      <https://www.gnu.org/software/gnulib/manual/html_node/gettextize-and-autopoint.html>.
    + Use the 'gettext' module.
  + If your project cares more about ease of development on older platforms:
    + gettext 0.17 or newer.
    + Use the 'gettext-h' module.
  + Recommended.
    Needed if you use modules that use internationalization (many do).
  + Homepage:
    https://www.gnu.org/software/gettext/
  + Download:
    https://ftp.gnu.org/gnu/gettext/

* Bison 2.0 or newer.
  + Recommended.
    Needed if you use the 'parse-datetime' module.
  + Homepage:
    https://www.gnu.org/software/bison/
  + Download:
    https://ftp.gnu.org/gnu/bison/

* GNU gperf 3.0.1 or newer.
  + 3.0.1 or newer is mandatory, but 3.1 or newer is recommended.
    Needed if you use the 'iconv_open' module.
  + Homepage:
    https://www.gnu.org/software/gperf/
  + Download:
    https://ftp.gnu.org/gnu/gperf/

* Texinfo 4.6 or newer.
  + Recommended.
    Needed if you use modules that include documentation.
  + Homepage:
    https://www.gnu.org/software/texinfo/
  + Download:
    https://ftp.gnu.org/gnu/texinfo/

* GNU sed.
  + Recommended.
    Needed on platforms where the vendor's 'sed' program is too buggy.
  + Homepage:
    https://www.gnu.org/software/sed/
  + Download:
    https://ftp.gnu.org/gnu/sed/

* GNU libtool 1.5.22 or newer.
  + Optional.
    Needed if you want to invoke gnulib-tool with option --libtool.
    libtool 2.2.x or newer is needed if you want to invoke gnulib-tool
    with options --create-testdir/--test  and --libtool.
  + Homepage:
    https://www.gnu.org/software/libtool/
  + Download:
    https://ftp.gnu.org/gnu/libtool/