Linux is everywhere. I use it, and so do you. We all do. If not on your laptop, probably on your phone, TV, or some connected accessory. You may also be a GNU/Linux convert, advocate, or even developer. Whichever your exact scenario may be, we are all riding the Linux wave in a way or another. This text is meant for you, fellow free software campaigner, FOSS system administrator, open source hacker, opinionated LKML reader, GNU power user or occasional tech enthusiast of any flavour, as we all share common legacy, collective ancestry, whether we know it or not.

Say you use Linux as a daily driver, and find it amazing? It is; and so are others! Heard the “Linux revolution” changed everything? It did; not quite by itself! Read that Linux is “superior”, morally or technically? It may be; though only part of a much larger story! Believe GNU/Linux to be the rebel alliance fighting the Empire? It certainly used to be; the landscape has shifted, in all honesty. Sense that Linux is all we talk about at the system layer? Yes, quite frankly; sadly so, if you ask me. Now, you may have wondered how each moving part of Linux came to be? Yes or no, what if we took a peek under the hood, and let it tell us a story?

Hey ho, let’s go!

Dense & layered genealogy

$user

Drag’n’dropping windows in a GUI daily? Wayland today, X11 yesterday: it all started with MIT’s Project Athena in 1983. On your desktop still, most anything you see in 3D speaks OpenGL, which was born on SGI’s UNIX in 19921. Speaking of graphics, if Doom or Quake rocked your world in the 90s like it did mine, know that id Software developed both games on NeXTcube, the legendary UNIX black box that took the world by storm in that era2. Back to text, what about terminal rendering colors, cursor moves, escape codes? termcap in 4BSD (1978) → terminfo by Mary Ann Horton in System V3.

$sysadmin

Connecting to a server over ssh? You’re using OpenSSH, created by OpenBSD4. Attaching a tmux session? OpenBSD again. Your distro ships LibreSSL? OpenBSD once more, cleaning up OpenSSL after Heartbleed. Rendering man pages on Alpine Linux? mandoc, from OpenBSD too. Editing with vi, vim or nvim? You have Bill Joy to thank for it (BSD, 1976)5. Your packet filter? nftables modernized iptables in OpenBSD pf’s declarative spirit6. Scheduling tasks? cron, BSD (1987). Resolving DNS? gethostbyname, 4.3BSD (1986). Running a nameserver? Probably BIND, 4.3BSD too, then ISC. The boring infrastructure of every Linux server relies on this very lineage.7

$archivist

Mounting directories over NFS? You’re talking to SunOS code from 19848. Accessing Linux files from Windows in WSL2? 9P, Plan 9’s network file protocol from 19899. Running ZFS on your NAS, overhearing experts say it’s all the rage? Born in Solaris 20+ years ago, kept open and refined by illumos, made cross-platform by OpenZFS!10 Btrfs and bcachefs have been trying to catch up ever since11. Heard good things about XFS? Born within SGI12 IRIX in 1994. JFS? AIX from IBM, 1990. Managing logical volumes with LVM? HP-UX (1992). Using the Linux default? ext2 was directly modeled on FFS, the 4.2BSD Fast File System from 1983.

$devops

Firing up OS or application containers? FreeBSD pioneered the concept in 2000 with jails13, Solaris Zones refined it in 2004, years before LXC14. Docker made it ubiquitous, but Joyent had been running unmodified Linux binaries via lx-branded zones since 200815. While Docker for Mac ran on a port of FreeBSD’s bhyve hypervisor16, the kernel primitives — mount namespaces & clone(2) — trace back to Plan 9 (1989)17. Overlayfs, the layer storage every Docker image stacks on? Plan 9’s union directories. Booting through systemd? Inspired by launchd from macOS, prefigured by SMF from Solaris18.

$programmer

Debugging with bpftrace? Half 4.4BSD (BPF, 1992), half Solaris (DTrace language)19. Capturing packets with tcpdump? libpcap from 4.4BSD. Writing Go20? Limbo descent, the language of Inferno (1996)21. Compiling with clang/LLVM? Darwin needed a non-GPL alternative to gcc, and Linux inherited the result22. The toolchain itself? GNU’s userland was written across 40 years by hundreds of contributors, predating the Linux kernel by a decade23. Building Gentoo Linux with Portage? Modeled on FreeBSD ports (1994). Installing software via pkgsrc? NetBSD, 1997, first cross-platform packaging system ever, still maintained to this day24.

$netsurfer

Sending texts in UTF-8? Pike & Thompson at Plan 9 (1992)25. Accessing the Internet? Every TCP/IP stack inherits 4.2BSD’s design (1983)26. The BSD sockets API is forty-plus years old and unchanged, macOS’ stack still uses BSD code, and even Windows NT did so for a while27. Plugging a printer or a speaker? Apple invented mDNS, known on Linux as Avahi28. Running Firefox or Android? jemalloc from FreeBSD. Navigating the web? Tim Berners-Lee built the first browser & the first web server on NeXTSTEP at CERN in 199029, whose own TCP/IP was BSD-derived. The protocols, the first server, the first browser… none of it was Linux.

Linux, alone in the cosmos?

A world teeming with life

Look closer. While Netflix & Sony’s PlayStation running FreeBSD may be common knowledge by now30, the rest of the iceberg is less visible. Messaging? Hotmail31 & WhatsApp32 ran on FreeBSD as well. Juniper’s routers? FreeBSD here too33. Time Capsule backups? NetBSD (just like your toaster, maybe?)34. Driving? Your car’s dashboard probably runs QNX. Processing? Intel CPUs have silently embedded MINIX 3 since 201535, though probably not for a good reason. However nefarious this may be, the teaching OS Torvalds learned UNIX on became one of the most-installed operating systems on the planet, bypassing his own by a margin!

The point is not to belittle Linux, nor to revive the OS wars36. GNU/Linux has become indispensable37, and so have the Linux-native components: cgroups, the scheduler, KVM, drivers for everything that ships. But some of the features getting praised are things GNU/Linux received38, rather than things it originated. Whenever you celebrate the running system, you are also celebrating all of the BSDs, Solaris & illumos, Plan 9 & the original UNIX, amongst others — whether you know them or not, whether you like or not, whether you care about them or not. I do think you should care, especially if you value Linux: it’d be nowhere near where it is now without the tireless contributions of these other systems — their devs, sponsors, communities — some of whom had little to nothing to gain, but did it anyway. Naming them is the least we can do.

Linux is everywhere, it is true: Linux workloads power most of the cloud, dominate datacentres, and ping from people’s pockets through Android all across the world. But it is definitely not alone, and the other half or so quietly runs something else in the background: from Apple deploying UNIX at scale39 to most (if not all) of the aforementioned projects pushing forward in distinct capacities, the linuxification of systems is certainly not absolute. Redox & Asterinas are rebuilding UNIX & Linux from scratch in Rust, SerenityOS40 & Genode in C++. 9front resurrected Plan 9 into a lively, irreverent community of creative hackers41, Haiku carries BeOS forward, and a handful of volunteers somehow keep the GNU Hurd afloat after thirty-plus years42.

Meanwhile, Oxide folks seem to be channeling the free-spirited creativity and reverence for the “days of the UNIX workstation” (explicitly à la Sun43) to bridge past, present, and future, enabling old & new generations of engineers to advance the UNIX tradition44. They have shown that it’s still possible to build a vertically-integrated computer company: shipping hyperscaler-grade racks for on-premise cloud, powered by their own illumos distro, Helios45. Far from fighting Linux, they enable it at scale, and they do so by committing to an ecosystem many dismissed as a relic. Going against the grain, Oxide founders deemed Solaris’ primitives, history, and engineering quality the right toolset for the problem they set out to solve46. Looks like diversity is recombining, not dying!

Carriers across motives

From creative tinkerers on campuses amidst the psychedelic era to early digital counter-cultures, from open source as an embodiment of collective intelligence to cyberspace utopias, from hackerspaces to server collectives & community ISPs… the UNIX legacy enabled much more than the polished “Linux revolution” narrative tends to bury: free software was never just about software. The very motions that enabled the plural-OS substrate we’ve been documenting — refusing monoculture, distributing power, treating users as participants rather than products — encompass social, technical & political propositions that go beyond mere engineering problems: tech can be for the people, by the people, not just deployed onto them.

As partial as our inventory may be, another pattern emerges clearly: FOSS has worked across motives that don’t always coexist easily. From long-running FSF copyleft & BSD permissive rivalry to DARPA-funded 4.xBSD or NSA-written SELinux, from commercial vendors paying engineers to individual maintainers writing Vim or GnuPG mostly unfunded for a quarter of a century, from big tech contributing for strategic reasons that simultaneously benefit the commons to stewardship companies funding engineering on non-mainstream lineages because they believe in correctness above all else, it’s not just radical hackers or industry. It’s a multi-motive ecology of ecosystems whose natural habitats vary greatly, and yet, overlap tactically. Cross-pollination works, whether the carriers are libre software activists, open source practitioners, commercial vendors, university researchers, defense contractors, lone maintainers or strategic-corporate actors: what gets carried outlasts whoever carried it.

Either way, none of the aforementioned projects, however focused & opinionated their devs may behave, however hellbent on rc.d vs systemd their userbase may be, however welcoming their space may have become to keyboard rebels fleeing those who raged against the machine yesterday, only to become its cogs today… none of them need to displace Linux in order to preserve option-value: the resilience monoculture cannot offer when commercial collapse, vendor lock-in or political capture come for you. Each is sustained by communities doing real maintenance, often unpaid, mostly unseen, be it NetBSD porters keeping a fifty-architecture codebase clean, OpenZFS folks keeping the tree across platforms47, or dozens of others doing the tedious work nobody else does. The connective tissue that enabled this history — POSIX, IETF protocols, codified formats — is still there because people who care tend to it. Standards & stacks don’t maintain themselves. Cross-pollination is what living systems do, and monoculture tends to be what dying ones do.

Tending the ecology

Whether the substrate lives & grows in density is up to us. We can be the people who use it, maintain it, fund it. The people who cross-compile for platforms that shouldn’t be left behind. The people who run non-aligned systems instead of going down the beaten path. The people who contribute code & documentation, time & dedication, art & songs48, heart & mind. The people who test and drive, who speak and write about these projects, past & present, so they can’t be wiped from collective memory, so the contributors feel the love and keep building, so the servers keep humming while the workloads keep flowing. This is an invitation to widen our scope, reclaim our history, acknowledge the depth of our collective foundations, so they can no longer be faded into invisible contributions. Let’s stay humble, curious, adventurous: if you walk away from this read willing to give one of these systems a spin, I’ll take that as a win!

Cross-pollination isn’t a state. It’s a practice. Don’t stay in your lane, become part of the broader UNIX family!

Our call, your call!

May 2026, veg,
longtime sysadmin,
#foreverlearning practitioner,
UNIX Social Club founder

Notes & references

  1. OpenGL was released by SGI as an industry standard in 1992, derived from their proprietary IrisGL (1982); those roots still drive the graphics stack on Linux desktops. ↩︎

  2. doom (1993) & quake (1996) were both developed by John Carmack & John Romero on NeXTcube workstations. Doom itself, originally a NeXT app, has since become the de facto standard for cross-platform portability, running on pretty much anything with a microcontroller, from pregnancy tests to IBM mainframes, catalogued on r/itrunsdoom. ↩︎

  3. Mary Ann Horton designed terminfo at AT&T (1981–82), included in System V Release 2. Every Linux terminal still uses her work. The New Curses and Terminfo Package (USENIX Summer 1982) is the canonical paper. ↩︎

  4. OpenSSH was forked from the last freely-redistributable release of Tatu Ylönen’s original SSH (1995), maintained by OpenBSD since 1999, used on every Linux server’s ssh connections since! ↩︎

  5. vi: Bill Joy at Berkeley, originally as a visual mode of ex (1976); shipped as a distinct command in 2BSD (1978). Joy went on to co-found Sun Microsystems in 1982, carrying the BSD line with him: vi, csh, the BSD socket layer & FFS became Sun’s foundation, made universal by POSIX. ↩︎

  6. OpenBSD pf ships across all the BSDs and as macOS’s default firewall since Lion (2011), via FreeBSD’s port. Millions of Mac users run an OpenBSD firewall without knowing it. Originally written in 2001 to replace IPFilter after a licence dispute. ↩︎

  7. Paul Vixie’s cron (1987, BSD-distributed) is the universal scheduler ancestor. BIND started at UC Berkeley (1984), shipped in 4.3BSD (1986), and migrated to ISC in 1996, where it is still maintained. The resolver library (gethostbyname, getaddrinfo) is what every Linux process uses for name resolution. ISC also ships dhcpd & dhclient, the BSD-style licensed DHCP suite most Linux distros defaulted to for years. ↩︎

  8. NFS shipped in SunOS 2.0 (1984; NFSv2 spec 1989). The network file protocol anchored a generation of UNIX deployments and still anchors most Linux storage interop today. Sun’s broader contributions to the Linux substrate run much deeper (see 43). ↩︎

  9. Plan 9 was Bell Labs’ « what if we did UNIX again? » project at the Computing Sciences Research Center, designed & built primarily by Ken Thompson, Rob Pike, Dennis Ritchie, Phil Winterbottom, Dave Presotto, Tom Duff, plus Russ Cox & others later on. The design lessons (per-process namespaces, 9P, UTF-8) trickled down into UNIX-family systems and modern networking. Plan 9 stayed niche, but its ideas sure didn’t! ↩︎

  10. ZFS shipped in Solaris 10 6/06 (2006); after Oracle closed Solaris in 2010, illumos kept the source tree open, acting as the upstream zfs for FreeBSD, macOS & ZFS-on-Linux ports, up until OpenZFS 2.0 (late 2020) led one of the most ambitious & sustained open source inter-OS code collaborations in modern computing, becoming the reference codebase for most systems. ↩︎ ↩︎ ↩︎

  11. macOS also ended up catching up to ZFS: after announcing ZFS as the future filesystem of macOS in 2007, Apple quietly switched gears in October 2009, and APFS is the in-house redesign that resulted. ↩︎

  12. SGI ported XFS to Linux themselves in 2001. ↩︎

  13. FreeBSD jails shipped in FreeBSD 4.0 (March 2000) and proved to be the first production OS-level container, predating LXC (2008) and Docker (2013) by 8–13 years. While the Kamp+Watson SANE 2000 paper is the foundational primary, Bryan Cantrill’s “On Jails and Solaris Zones” (Papers We Love NYC, March 2016) offers an energetic retelling of the road to modern containers. ↩︎

  14. Solaris Zones shipped in Solaris 10 beta (February 2004). One can argue it is the conceptual ancestor of Linux cgroups (2008). The Price+Tucker LISA 2004 paper is the foundational primary. ↩︎

  15. SmartOS (2011) is Joyent’s illumos-derived hypervisor OS that productised lx-branded zones for cloud workloads. Triton DataCenter (open-sourced 2014) is its cluster-orchestration layer, an alternative to Kubernetes. ↩︎

  16. xhyve is the macOS port of FreeBSD’s bhyve hypervisor. ↩︎

  17. Plan 9 namespaces (1989+) are where Linux’s mount namespaces, clone(2), and overlayfs primitives reach back to. Continued in 9front. ↩︎

  18. SMF (Service Management Facility, Solaris 10, January 2005) & launchd (macOS 10.4 Tiger, April 2005) shipped the same year, both predating systemd (2010) by half a decade. Lennart Poettering openly cited launchd as direct inspiration for systemd in his 2010 essay “Rethinking PID 1”. ↩︎ ↩︎

  19. DTrace in Solaris (2003); cross-OS port chain Solaris → macOS Leopard (2007) → FreeBSD → bpftrace on Linux (2018). The Cantrill+Shapiro+Leventhal USENIX 2004 paper is the foundational primary, and “DTrace at 21” (P99 CONF, 2024) adds Cantrill’s retrospective 20+ years later. ↩︎ ↩︎

  20. Russ Cox worked on Plan 9 at Bell Labs before joining the Go team at Google, carrying Plan 9’s design sensibility forward. Rob Pike, Ken Thompson & Robert Griesemer co-led the original Go design, whose concurrency model descends directly from Limbo (Inferno’s language 21) & CSP. ↩︎ ↩︎

  21. Inferno is a distributed OS born at Bell Labs (1995–96), designed by Rob Pike, Phil Winterbottom, Sean Dorward, Howard Trickey and others as a Plan 9 follow-up tailored for networked devices. In addition to its channels & goroutines concurrency model fostering Go20, its Styx protocol became Plan 9’s 9P2000. Stewarded by Vita Nuova; now community-maintained on GitHub. ↩︎ ↩︎

  22. LLVM started as Chris Lattner’s PhD work at the University of Illinois at Urbana-Champaign (2000), Apple-sponsored from 2005 to provide a non-GPL toolchain for Darwin, iOS & macOS. ↩︎

  23. Stallman announced the GNU project on 27 September 1983, eight years before the first Linux kernel release. By 1991, most of “Linux’s userland” already existed and ran on commercial UNICES (gcc, emacs, bash, coreutils). The proprietary turn at MIT AI Lab (1981–82) precipitated Stallman’s commitment to building software users could read, study, modify & share, leading him to found GNU. The GPL family is the legal framework of the Linux kernel & most of GNU/Linux’s userland, sustained by the FSF (1985+). ↩︎

  24. pkgsrc was created at NetBSD in 1997: the first cross-platform package management system, descended from FreeBSD’s ports (1994). ↩︎

  25. UTF-8 was designed by Rob Pike and Ken Thompson in September 1992 over dinner at a New Jersey diner during Plan 9 development; the original design was sketched on a placemat. Standardised through IETF and Unicode; the text encoding of the modern internet. See Pike’s account. ↩︎

  26. TCP/IP shipped in 4.2BSD (1983); the design and the early code are Berkeley’s. Linux’s stack is clean-room but follows the Berkeley design. The 1992–1994 CSRG vs USL lawsuit and the 1994 4.4BSD-Lite settlement 36 produced the legally-redistributable codebase from which FreeBSD, NetBSD, OpenBSD, and Darwin descend. ↩︎

  27. the early NT networking stack drew on BSD code (uncredited at the time), amidst a quarter-century of hardline anti-FOSS hostility: the leaked Halloween Documents detailed a strategic war against open source, Steve Ballmer’s infamous “Linux is a cancer” line, the reportedly indirect funding of SCO’s legal campaign against Linux. Years later, corporate opportunism led to a hilarious reversal when cloud-economics flipped: a sudden “we love Linux now” pivot for Microsoft, which subsequently became a top-15 Linux kernel contributor, shipped WSL2 (a Microsoft-maintained Linux kernel) to billions of Windows desktops, and acquired GitHub. The substrate may have absorbed the contributions either way, but absorption is not absolution, and the campaign that preceded it can’t be erased by retroactive git commits. ↩︎

  28. Apple introduced Bonjour (mDNS, DNS-SD) in 2002, IETF-standardised. Avahi is the re-implementation that ships in every Linux distro. ↩︎

  29. Tim Berners-Lee proposed the Web at CERN in March 1989; the first web server, the first browser (WorldWideWeb), and the first website went live in late 1990 on a NeXTSTEP workstation. CERN preserves the original NeXT cube with its hand-written “This machine is a server. DO NOT POWER IT DOWN!!” sticker. ↩︎

  30. Netflix Open Connect has run on FreeBSD since ~2012, its engineers contributing upstream. Sony’s PlayStation has shipped a BSD-derived OS from the PS3 onwards; a short-lived OtherOS feature ran Linux as a guest, but is sometimes confused with the system OS, which was always BSD. ↩︎

  31. Hotmail launched July 1996 on FreeBSD, was acquired by Microsoft in December 1997, who claimed the service’s migration to Windows 2000 was complete in June 2001, but later admitted DNS still ran on FreeBSD; full transition was not done until ~2002, as Windows NT could not handle the workload at scale for years (see The Register’s account of the migration). ↩︎

  32. WhatsApp’s high-density Erlang/FreeBSD architecture served billions of messages with a small engineering team before it was acquired by Facebook in 2014. FreeBSD persisted in the WhatsApp stack until ~2017 (see WhatsApp engineering’s classic “1 million is so 2011” on Erlang scale). ↩︎

  33. Junos has been FreeBSD-derived since 1998 (Juniper engineers contributing upstream), which means a decent chunk of the internet between Linux servers transits FreeBSD-derived routers. ↩︎

  34. Apple’s AirPort Extreme & Time Capsule firmware uses NetBSD. The “of course it runs NetBSD” tagline (covering printers, satellites, vending machines, ATMs, toasters…) reflects NetBSD’s 50+ supported-architectures portability ethos. ↩︎

  35. Intel ME 11 (Skylake, 2015) was the first generation to run MINIX 3; the deployment was publicly disclosed in 2017, prompting Tanenbaum’s open letter to Intel. ↩︎

  36. The OS wars of the 1990s, specifically the UNIX wars, happened amidst a critical lawsuit that kept the BSDs in legal limbo for several years (1992–1994), preventing adoption at the same time Linux was gaining traction. By the time the 4.4BSD-Lite settlement allowed the BSDs to be unambiguously & cleanly redistributable (1994), Linux had captured a critical mass of developers. The “Linux headstart” was partly an effect of timing & paralysing legal attacks. ↩︎ ↩︎

  37. Linux’s specific rise is read several ways, beyond the timing and absorption factors. Commonly invoked mechanisms include commodity x86 hardware support at the height of the PC-clone era, the GPL’s reciprocity-mandate forcing derivatives to feed the upstream tree, and a “worse is better” shipping discipline (Richard Gabriel) as opposed to the correctness first patience characterizing most of the other UNICES. ↩︎

  38. The downfall of commercial UNIX has consistently fed Linux. SGI’s long Linux pivot through decline seeded XFS, the OpenGL/DRI/Mesa graphics chain, cpusets & NUMA scaffolding into mainline before its 2006 bankruptcy. Sequent’s IBM acquisition (1999) shipped RCU, now core to Linux kernel synchronisation. Sun’s Oracle takeover (2010) closed Solaris but routed ZFS through illumos into ZoL (ZFS-on-Linux). Apollo’s HP acquisition (1989) seeded Samba’s secondary wire format. DEC’s Tru64 wind-down (1998–2002) seeded the Alpha port that made Linux 64-bit-clean before x86_64 existed. Whenever a commercial vendor declined or folded, its engineers, code & design lessons flowed downstream, and Linux was the main absorption surface. ↩︎

  39. macOS is officially UNIX-certified by The Open Group, a status held since macOS 10.5 Leopard (2007). GNU/Linux is not: UNIX-like but not certified, likely because no distribution has paid for and passed conformance testing. ↩︎

  40. SerenityOS spawned Ladybird, forked into its own non-profit in 2024 by Andreas Kling: a rare new independent browser engine alongside Chromium, WebKit, and Gecko. ↩︎

  41. Plan 9 from Bell Labs development wound down around 2002, and the system was open-sourced. Circa 2011, 9front revived active development as a community fork. ↩︎

  42. GNU Hurd is GNU’s never quite finished kernel, Mach-based, in development since ~1990. Debian GNU/Hurd ports continue, and the project is alive but slow. Linux did become GNU’s working kernel by historical accident. ↩︎

  43. Sun’s contributions to the Linux substrate run much deeper than NFS: PAM, NSS, the VFS+vnode model, the slab allocator, the Solaris privilege model, kstats-style structured kernel counters, DTrace (see 19), SMF (see 18) & ZFS (see 10). ↩︎ ↩︎

  44. Bryan Cantrill’s “Fork Yeah! The Rise and Fall of OpenSolaris” talk (USENIX LISA 2011) provides an articulate retelling of the Sun-to-Oracle transition: engineering culture, the OpenSolaris closure, and the founding of illumos as their living continuation, told by someone who was there. ↩︎

  45. Oxide Computer (2019+) ships an integrated server-rack product with a deliberately open everything stack: the first commercial server vendor in this generation to do so. Oxide engineers contribute upstream to illumos-gate. Oxide’s On the Metal podcast collects firsthand stories from industry veterans across hardware/OS history. ↩︎

  46. Oxide’s RFD 26 documents the founding team’s rationale for the illumos commitment in their own words. RFDs (Requests for Discussion) are Oxide’s public design-doc format, modelled on IETF RFCs. ↩︎

  47. Jeff Bonwick & Matt Ahrens (ZFS co-architects) led the team at Sun; when Oracle close-sourced Solaris in 2010, they migrated to Delphix and other stewardship companies, carrying the work forward in open form (see 10). ↩︎

  48. OpenBSD ships release artwork and an original song with every release: a tradition where each version has its own theme, cover art, and song. ↩︎