Incomplete list of downstreams including dpkg in their distribution (which are not tracked currently by the PTS). Interesting changes found on their packages might include portability and bug fixes.

Debian derivatives:

GNU/Linux:

(1.21.x)

ALT Linux

(1.21.x)

AOSC

(1.22.x)

Arch Linux

(1.19.x)

Endless Mobile

(1.21.x)

Exherbo

(1.21.x)

Fedora

(1.21.x)

Gentoo

(1.22.x)

GNU Guix

(1.19.x)

GoboLinux

(1.21.x)

Mageia

(1.22.x)

NixOS

(1.22.x)

OpenEmbedded

(1.22.x)

openmamba

(1.21.x)

OpenMandriva

(1.22.x)

OpenSUSE

(1.18.x)

PCLinuxOS

(1.21.x)

PLD Linux

(1.22.x)

Slackware

(1.17.x)

SliTaz

(1.21.x)

Solus

(1.19.x)

Source Mage

(1.22.x)

T2

(1.22.x)

UHU-Linux

(1.22.x)

Yocto Project

(1.22.x)

Void Linux

musl/Linux:

(1.22.x)

Alpine Linux

Android/Linux:

(1.22.x)

Termux

BSD:

(1.19.x)

FreeBSD

(1.19.x)

DragonFlyBSD

(1.22.x)

NetBSD

Solaris:

(1.15.x)

OpenCSW

Illumos:

(1.19.x)

Dilos

(1.20.x)

OS Dyson

Darwin:

(1.18.x)

Cydia

(1.10.x)

Fink

(1.22.x)

Homebrew

(1.21.x)

MacPorts

Multi-platform:

(1.22.x)

Ravenports

See also the output of whohas dpkg or the dpkg Repology metapackage.

Legend

development (1.22.x)

stable (1.21.x)

old stable (1.20.x)

legacy (1.19.x, 1.18.x, 1.17.x; supported by third-party)

ancient (unsupported)