Operating Systems

Operating Systems#

Reference of operating systems an operator may meet, organized by family. Each entry lists the variant, kernel, package format, typical install base, and the operator-relevant detail (init, default shell, etc.).

For Linux distribution detail, see Linux. For file systems, see Filesystems. For container runtimes, see Containers.

Linux distributions#

Distribution

Kernel

Package format

Notes

Ubuntu

Linux

deb (apt)

Most-deployed Linux on cloud + desktop; Standard; LTS every 2 years (24.04 / 26.04).

Debian

Linux

deb (apt)

The upstream of Ubuntu; renowned stability.

Linux Mint

Linux

deb (apt)

Ubuntu-derivative; desktop-friendly.

Pop!_OS

Linux

deb (apt)

System76; gaming + dev-focused.

Kali

Linux

deb (apt)

Pentest-distro (Debian-based).

Raspberry Pi OS

Linux

deb (apt)

Pi-targeted Debian.

RHEL

Linux

rpm (dnf / yum)

Red Hat Enterprise Linux; the enterprise standard; subscription-based.

CentOS Stream

Linux

rpm (dnf)

RHEL upstream rolling.

Rocky Linux

Linux

rpm (dnf)

RHEL-rebuild after CentOS shift.

AlmaLinux

Linux

rpm (dnf)

RHEL-rebuild.

Fedora

Linux

rpm (dnf)

RHEL upstream; bleeding-edge.

openSUSE Leap /

Linux

rpm (zypper)

SUSE community; Leap = stable, Tumbleweed =

Tumbleweed

-

-

rolling.

SLES

Linux

rpm (zypper)

SUSE Linux Enterprise.

Arch Linux

Linux

pacman

Rolling release; minimalist.

Manjaro

Linux

pacman

Arch derivative; user-friendly.

EndeavourOS

Linux

pacman

Arch derivative.

Gentoo

Linux

portage (emerge)

Source-based.

Slackware

Linux

tarball + slackpkg

The oldest still-active distro (1993).

NixOS

Linux

nix (declarative)

Atomic upgrades; functional package mgmt.

Alpine Linux

Linux (musl)

apk

Tiny; container-favorite (5 MB base image).

Amazon Linux

Linux

rpm

AWS-tuned; based on Fedora.

Photon OS

Linux

tdnf

VMware-tuned for container hosts.

ChromeOS / Flex

Linux

portage-style

Google.

Talos Linux

Linux

immutable

Kubernetes-only OS; API-managed.

Bottlerocket

Linux

immutable

AWS container OS.

Flatcar Container Linux

Linux

immutable

CoreOS continuation.

QubesOS

Linux + Xen

varies

security-by-isolation (Xen VMs).

Tails

Linux

deb

amnesic privacy-focused live USB.

Whonix

Linux

deb

Tor-routed two-VM workflow.

Parrot OS

Linux

deb

pentest distro alt to Kali.

BlackArch

Linux

pacman

Arch-based pentest.

BSD family#

OS

Kernel

Package format

Notes

FreeBSD

FreeBSD

pkg

Server / network-appliance favorite.

OpenBSD

OpenBSD

pkg

Security-focus; pf firewall origin.

NetBSD

NetBSD

pkgsrc

Maximum portability; “of course it runs NetBSD”.

DragonFly BSD

DragonFly

pkg

FreeBSD fork; HAMMER fs.

TrueNAS Core / Scal e

FreeBSD / L

inux

NAS appliance; Scale is Linux-based now.

pfSense

FreeBSD

pkg

firewall / router appliance.

OPNsense

FreeBSD

pkg

pfSense fork.

macOS / iOS#

Release

Notes

Mac OS X 10.0

Cheetah (2001).

… 10.6 - 10.15

Snow Leopard … Catalina; “OS X” branding.

macOS 11 Big Sur

2020; Apple Silicon transition.

macOS 12 Monterey

macOS 13 Ventura

macOS 14 Sonoma

macOS 15 Sequoia

macOS 16 … 26

2025+; ongoing yearly cadence.

iOS / iPadOS

Apple mobile OS; same Darwin kernel as macOS.

visionOS

Vision Pro spatial OS.

watchOS, tvOS

derivatives.

Darwin (FreeBSD-derived) is the kernel; XNU is the hybrid Mach + BSD kernel; APFS is the modern filesystem.

Windows#

Release

Notes

Windows 7

2009; EOL 2020 (extended 2023 paid).

Windows 8 / 8.1

2012-13; Metro UI.

Windows 10

2015; LTSC variants (1607, 1809, 21H2, …) extended-support.

Windows 11

2021; TPM 2.0 + Secure Boot required.

Windows 12

~2025+ (rumoured cadence).

Windows Server 2016

/ 2019 / 2022 / 2025 parallel server line.

Windows Server

Core (no GUI) and Desktop Experience flavours.

Windows IoT

Enterprise + LTSC; embedded.

Windows on ARM

Snapdragon X Elite + Apple Silicon Parallels VMs.

Mobile / embedded#

OS

Notes

Android (AOSP)

Linux kernel; per-device Google / vendor builds.

Android Auto / TV /

Wear / Auto / Things , variants.

GrapheneOS, /e/OS, LineageOS, CalyxOS, DivestOS

privacy-focused Android distributions.

HarmonyOS (Huawei)

Linux + Hongmeng kernel; PRC-mainland.

KaiOS

feature-phone HTML5 OS.

Tizen (Samsung)

IoT + smart-home.

WebOS (LG)

smart TV.

QNX

microkernel; vehicles, medical, real-time.

VxWorks

real-time embedded.

FreeRTOS

tiny RTOS for microcontrollers.

Zephyr

Linux Foundation RTOS for IoT.

Mbed OS

ARM IoT OS.

RIOT, NuttX, FreeRT OS-Plus

embedded.

ESP-IDF / FreeRTOS

on ESP32 / ESP8266.

Unix-like history#

Year

Release

1969

Unix v1 (Bell Labs).

1973

Unix v4 rewritten in C.

1977

BSD 1.

1983

System V.

1987

Minix.

1991

Linux 0.01.

1992

Linux 0.95 (GPL).

1993

FreeBSD, NetBSD.

1994

Linux 1.0; Slackware, Debian, SUSE.

1995

OpenBSD; Red Hat Linux.

1996

Linux 2.0.

2003

Linux 2.6.

2008

Android 1.0.

2011

Linux 3.0.

2016

Linux 4.0.

2019

Linux 5.0.

2024

Linux 6.x maintained; immutable distros mainstream.

Identification quick-look#

Detection

Notes

uname -a

Linux + BSD + macOS kernel + arch.

/etc/os-release

systemd-style distro identification.

/etc/lsb-release

legacy Ubuntu / Debian.

/etc/redhat-release

RHEL family.

cat /proc/version

kernel build string.

hostnamectl

systemd CLI; rich per-host info.

sw_vers

macOS.

ver

Windows cmd.

[Environment]::OSVersion

PowerShell.

ssh-banner /

remote OS often inferred from SSH version.

nmap -O

OS-fingerprint scanning.

Operator notes#

  • Immutable distros (Talos, Bottlerocket, Flatcar, Photon) are increasingly the right pick for container hosts, no package manager, atomic upgrades, smaller attack surface.

  • musl vs glibc, Alpine uses musl; some binaries expect glibc and break.

  • Init systems, systemd dominates; runit (Void), OpenRC (Gentoo), s6 (Alpine), launchd (macOS), SMF (illumos) all exist.

  • Default shells, bash on most Linux, zsh on macOS since Catalina, ash on Alpine, ksh93 on AIX, cmd.exe / PowerShell on Windows.

  • EOL dates matter, RHEL 7 EOL Jun 2024, Ubuntu 18.04 EOL May 2023, Windows Server 2012 / R2 EOL Oct 2023; track per regulatory framework.

References#

Contents