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IxoloIxolo

History

Ixolo is not a new operating system written from scratch. It is the latest branch of a code base that has been taught, studied and rewritten since 1984. Knowing that history explains a lot about the source tree: why there are three generations of comments in some files, why the user-space tools come from NetBSD, and why the version string still says 3.4.0.

The dates below come from the sources listed at the end of the page. Where a date only comes from file timestamps or press coverage, the table says so.

MINIX 1 and 2: a system for students (1984–2003)

Section titled “MINIX 1 and 2: a system for students (1984–2003)”

In 1984 Andrew S. Tanenbaum, a professor at the Vrije Universiteit (VU) in Amsterdam, began writing a UNIX-compatible system in his spare time. AT&T’s licence for UNIX Version 7 no longer allowed its source to be used in teaching, and he wanted a system small enough for students to read completely.

YearEvent
1987MINIX 1 is published together with the first edition of Operating Systems: Design and Implementation (OSDI). It is compatible with Version 7 UNIX, runs on the IBM PC, and is sold by Prentice Hall on floppy disks with a manual.
by 1991MINIX 1.5 has been ported to the Macintosh, Amiga, Atari and SPARCstation.
1991Linus Torvalds buys a PC to run MINIX, studies its source and posts to the comp.os.minix newsgroup. In August he announces there the hobby kernel that becomes Linux. Early Linux used the MINIX file system.
1992Tanenbaum’s post arguing that microkernels are the better design starts the famous microkernel-versus-monolithic debate with Torvalds on the same newsgroup.
1997MINIX 2, released with the second edition of OSDI (co-written with Albert S. Woodhull), targets POSIX instead of Version 7.
2000MINIX is relicensed under a BSD-style licence and can be downloaded freely. This is the licence Ixolo still uses.

Through all this time MINIX was already a microkernel system: the file system and memory manager ran as separate processes. The device drivers, however, were still compiled into the kernel image.

MINIX 3: reliability research at VU (2004–2016)

Section titled “MINIX 3: reliability research at VU (2004–2016)”

In 2004 the project changed from a teaching hobby into a funded research project on dependable systems. A grant from the Netherlands Organisation for Scientific Research (NWO), followed by an Academy Professorship from the Royal Netherlands Academy of Arts and Sciences, paid for a team. Jorrit Herder’s master’s work moved the drivers out of the kernel into isolated user-mode processes, and the reincarnation server was added to restart them when they fail. That combination, user-mode drivers plus self-repair, is what made it “MINIX 3”.

DateEvent
Oct 2005MINIX 3 is announced in Tanenbaum’s keynote at ACM SOSP 2005. 3.1.0, the version described in the book, is released on 24 October.
2006The third edition of OSDI (Tanenbaum & Woodhull) covers MINIX 3.1.0.
2006–20073.1.2a (May 2006) and 3.1.3 (April 2007), which introduces VFS, splitting the old file server into a virtual file system layer and file system servers such as MFS.
2008Tanenbaum receives a European Research Council Advanced Grant (no. 227874), which funds programmers, PhD students and postdocs for five years. A later ERC Proof of Concept grant (no. 297420) pays for the ARM port.
Jun 20093.1.4 adds virtual memory and the VM server.
2009–20103.1.5 (Nov 2009), 3.1.6 (Feb 2010, System Event Framework), 3.1.7 (Jun 2010, user-space scheduler), 3.1.8 (Oct 2010, pkgsrc and pkgin, ext2, ACPI).
2010Herder’s PhD thesis, Building a Dependable Operating System.
29 Feb 20123.2.0 switches to clang and the NetBSD C library, ELF binaries, a multithreaded VFS and the NetBSD boot loader, and adds experimental SMP. From here on most of the user-space tools come from NetBSD.
21 Feb 20133.2.1: shared libraries, the NetBSD build.sh cross-build, virtio and AHCI drivers.
2014PhD theses by Cristiano Giuffrida (live update) and Raja Appuswamy (the Loris storage stack).
Sep 20143.3.0, the first release that runs on ARM (BeagleBoard-xM, BeagleBone). It is also the last stable upstream release.
Jan 2016The tree is bumped to 3.4.0 and the first release candidate (rc1) is published.
Mar 2016Tanenbaum’s article “Lessons Learned from 30 Years of MINIX” in Communications of the ACM states that the research funding has ended and that MINIX is becoming a community open source project.

The research of this period (live update, fault injection, the Loris storage stack, multicore network stacks) is listed in Further reading.

The long pause (2016–2025)

Section titled “The long pause (2016–2025)”
DateEvent
2016–2017Six release candidates of 3.4.0 appear: rc1 and rc2 in January 2016, rc3 in December 2016, rc4 in January 2017, rc5 in March 2017 and rc6 on 9 May 2017. These dates come from the ISO file timestamps on the download server; there are no git tags for them. 3.4.0 final was never released.
late 2017Press reports reveal that a modified MINIX runs inside the Intel Management Engine (ME 11) on many PCs. Tanenbaum replied with an open letter: the BSD licence let Intel use it without telling him, and he would have liked to be told.
14 Nov 2018Last commit on upstream master.

The upstream repository has not been archived, but nothing has been merged since 2018. The website and wiki still list 3.3.0 as the current release. Its PC images are 32-bit only, and building the old tree with a modern host compiler is hard.

The 2026 fork, and Ixolo

Section titled “The 2026 fork, and Ixolo”

In March 2026 David Montero (David Montero) forked the upstream repository as davmont/minix on GitHub. The aim was to bring the system to 64-bit PCs without giving up what makes it worth studying: the small kernel, the isolated drivers and the self-repair.

Date (2026)Milestone
MarchThe fork starts with toolchain and code-health fixes and a resync of build tools with NetBSD 10.
late MayThe amd64 (x86-64) port boots to a login prompt. This first port is merged into master. All later work happens on the devel branch.
1–2 JuneA hybrid BIOS + UEFI boot CD built with GRUB, and SMP: the other CPUs are started and scheduled (PR #157), with an IPC fast path for sendrec.
JuneNVMe and USB mass-storage drivers, MSI-X interrupts, POSIX threads on amd64, and the switch to an in-tree LLVM/clang 22 with lld instead of GNU binutils.
24–27 JuneMFS version 4 (PR #246): wider inodes, files over 2 GB, dates past 2038. Then metadata journaling (PRs #251–#255), extended attributes and POSIX ACLs. MFS v4 becomes the default (PR #280).
JulyVirtual-memory work: clean-page reclaim, compressed anonymous memory and the kernel side of swap. lwIP is upgraded to 2.2.1.
13–14 Julywlcompd, a Wayland compositor written for the system, and Qt 6 rendering into it. The LXQt desktop experiments run from July to September.
late SeptemberA QEMU test harness runs the test suites in CI on every pull request.
OctoberPOSIX work: job control, kqueue, message queues, POSIX file-system tests. Hardening: stack protector, _FORTIFY_SOURCE, SMEP/SMAP, partial ASLR, OpenSSH 10.6. A 47-bit (128 TB) user address space. Real-time scheduling classes.
Novembertmpfs, shared memory across fork, thread cancellation. The Open POSIX Test Suite reaches 1645 of 1757 tests passing.
late 2026The project takes the name Ixolo.

Some items that upstream’s roadmap still lists as future work, such as a multicore kernel, now exist on devel. Some of what upstream had does not carry over: i386 no longer builds, the ARM port has not been touched since the fork, and the live-update feature has not been made to work on amd64.

To see what Ixolo looks like today, start with the architecture overview and the release notes.

Sources

Section titled “Sources”