Found on Sandra Snan's notice https://idiomdrottning.org/notice/AgXNxNMyxT1ZMgpLPM

Found via https://vlang.io/ → https://github.com/damon-kwok/v-mode → https://github.com/raxod502/straight.el
The programming language playground https://riju.codes/ looks interesting too.

See also https://github.com/vsedach/Vacietis and https://awesomeopensource.com/project/vsedach/Vacietis

Detailed description of the stack layout, use of R5 as frame pointer by the (V6) Unix C compiler on the pdp-11.

This repository contains a port of the "Ritchie C compiler" to the TI990 series processors, in particular the 9995 and 99105 chips. The port is currently fairly complete; only floating point operations remain unported. Other tool chain components (assembler, linker, etc.) are also provided.

The long term goal is to run ancient unix on these chips. As a first stepping stone on that journey, a port of the original 1983 version of the Xinu system has already been completed. The source for that is also in this repository.

Announced on TUHS mailing list https://www.tuhs.org/pipermail/tuhs/2021-February/023225.html

Interesting software, such as
unifdef selectively removes C preprocessor conditionals. My version of this program now shipped by all the BSDs (including Mac OS X) and is used by the Linux kernel build system.
regpg safely stores server secrets using gpg, so you can keep them in version control.
picoro - tiny coroutine implementations in pure C. I wrote an accompanying article, coroutines in 20 lines of standard C.
Counting the days - tiny routines for converting Gregorian dates into linear counts, like Julian day numbers or Unix time_t. The date of the count - a small routine for converting linear day counts into Gregorian dates.
https://dotat.at/@/2016-04-22-synergy-vs-xmodmap-fight.html Why you can't use xmodmap to change how Synergy handles modifier keys
https://dotat.at/@/2023-05-26-whence-time.html Where does my computer get the time from?
https://dotat.at/@/2023-08-04-unix69.html a neat keyboard map
https://dotat.at/@/2024-01-29-four-point-egg.html construct an egg shape with straightedge and compass
His log of links, https://dotat.at/:/ which I found on the TUHS mailing list is also worth reading. He explains a bit about this log on http://dotat.at/.

Found via SchemePlanet, where he announced the R6RS Scheme compiler Loko. It targets AMD64, either on bare hardware or under Linux.
Just one interesting example: https://weinholt.se/articles/non-posix-filesystems/

EISL was written by Kenichi Sasagawa
https://qiita.com/sym_num/items/793adfe118514668e5b0
The license appears to be similar to BSD/MIT to my non-laywer eyes: https://github.com/sasagawa888/eisl/blob/master/license.txt
It provides an interface to WiringPi, allowing control of the GPIO pins on a Raspberry π.