Main page is http://cowlark.com/cowgol/
It used to support the Apollo Guidance Computer used in the Apollo spacecraft, but I had to remove the code generator while rewriting the compiler and I haven’t reworked the AGC backend.
http://cowlark.com/2019-07-20-cowgol-agc/index.html
The author also ported the Fuzix operating system to the Raspberry π pico.
http://cowlark.com/2021-02-16-fuzix-pi-pico/index.html

His tool https://github.com/davidgiven/narcissus to remap keys might be interesting too.
So is his Forth system http://cowlark.com/fforth/

This document is a compendium of Casper Ti. Vector's thoughts about the Unix philosophy in the contemporary context.

Discussion of problems caused by unusual characters in filenames.
Found (again) via a link on the TUHS mailing list
https://www.tuhs.org/pipermail/tuhs/2024-June/030040.html

Hyper-linked and cross referenced rendition of the sources, much like doxygen or lxr does it. The desired features were:

cover boot, kernel, networking, library and user level code
cover C, assembler and other relevant languages with syntax highlighting
provide 'what is used where' information, over the whole system
provide hyperlinks for a fast code path analysis, especially across the user,library,kernel interfaces
support to follow the execution logic of a system call starting from user code, through the library layer, through the kernel interface, to the kernel code by just following hyperlinks.

Blog article about Android (FPOOS) on Fairphone 2.

On FreeBSD, OS X but not on Linux, C-T sends SIGINFO which produces information of the current process. Other interesting articles on the blog include
https://blog.danielisz.org/2017/03/18/the-unix-system-family-tree-research-and-bsd/
https://blog.danielisz.org/2018/02/10/raspbsd/
https://danielisz.wordpress.com/2018/02/11/raspberry-pi-and-freebsd/

The Mare Tranquillitatis People's Circumlunar Zaibatsu is an ideologically decriminalized world offering text-based asylum to those fleeing the commercialisation, bloat and surveillance of the wider net. The Zaibatsu offers 200MB of free gopherspace hosting to anyone who wants it for any non-commercial purpose. Gopherspace is managed via sftp. For further details, including instructions on how to request asylum, please visit circumlunar.space on port 70.

      In addition to functioning as a free gopher hosting provider, the
      Zaibatsu is also a small public access unix system.  A defining
      characteristic of this system is that much of the software used by the
      members for social interaction and other purposes is developed by the
      members themselves, collaboratively and openly, on the system itself.
      While only senior members can install software system-wide, *any* user
      with shell access can clone the git repo for some tool on the system,
      fix bugs or add features, and request their code be pulled into the
      system-wide repo.

Blog about Unix, C, system administration and more. See for example
https://utcc.utoronto.ca/~cks/space/blog/sysadmin/NotificationsVersusLogs
https://utcc.utoronto.ca/~cks/space/blog/sysadmin/IdentifyMachineEmailByRootName
https://utcc.utoronto.ca/~cks/space/blog/sysadmin/ProceduresAreNotDocumentation
https://utcc.utoronto.ca/~cks/space/blog/sysadmin/RCStoMercurial  Instructions for converting files/directories controlled with RCS to Mercurial.
TODO: mention M-x vc-revision-other-window. Saved Tue 2019-10-29 17:02:29
https://utcc.utoronto.ca/~cks/space/blog/unix/V7WhyItMattersSoMuch  found Mon 2022 -01-10 13:12:03 on https://irreal.org/blog/?p=10149
https://utcc.utoronto.ca/~cks/space/blog/linux/UbuntuKernelAutoremove  MIght want to see whether this is relevant for me. Saved Tue 2017-03-28 19:10:35

Found via a post on the TUHS mailing list
https://www.tuhs.org/pipermail/tuhs/2019-September/018465.html