Runs commands when system button/switch states trigger.

/e/OS is a complete, fully “deGoogled”, mobile ecosystem, an Android fork based on Lineage OS.

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.

Triggerhappy is a hotkey daemon that operates on a system wide scale. It watches all configured input devices for key, switch or button events and can launch arbitrary commands specified by the administrator. In contrast to hotkey services provided by desktop environments, Triggerhappy is especially suited to hardware related switches like volume or wifi control; it works independently from a specific user being logged in and is also suitable for embedded systems that do not a graphical user interface.
The source can be found on https://github.com/wertarbyte/triggerhappy

Squares RNG is a counter-based version of Middle Square Weyl Sequence RNG.  Counter-based RNGs have no state and are well suited to parallel processing.  There is no need to maintain or initialize a state.  Squares is faster than Middle Square Weyl Sequence on an Intel Core i7-9700.  Processing speed is, of course, processor dependent and may vary on other processors.  If you are currently using Middle Square Weyl Sequence, you might consider Squares.  It produces data of equivalent quality and is easier to use since there is no state.

This generator passes BigCrush and PractRand.

A pic preprocessor in awk for drawing circuit diagrams.

Found on Tony Finch's link log https://dotat.at/:/
There is also a nice introduction to TCP sockets at https://woozle.org/papers/sockets.html

Boot an UEFI machine over the network using the Plan 9 protocol.

Gemini is a new, collaboratively designed internet protocol, which explores the space inbetween gopher and the web, striving to address (perceived) limitations of one while avoiding the (undeniable) pitfalls of the other.

Found via Alex Schroeder's page https://alexschroeder.ch/wiki/Gemini

NomadBSD is a persistent live system for USB flash drives, based on FreeBSD®. Together with automatic hardware detection and setup, it is configured to be used as a desktop system that works out of the box, but can also be used for data recovery, for educational purposes, or to test FreeBSD®'s hardware compatibility.