Interesting blog written in org-mode, using https://github.com/bastibe/org-static-blog, written by Bastian Bechtold https://bastibe.de/
Some highlights:
https://jao.io/blog/eww-to-org.html convert HTML to orgdown
the links below probably need to be edited, removing the date
https://jao.io/blog/literate-programming.html literate programming
https://jao.io/blog/signel.html, a barebones signal chat on top of signal-cli, written in literate style
https://jao.io/blog/programmers-go-bananas.html category theory
https://jao.io/blog/dancers-at-the-end-of-time.html sounds like an interesting book.
https://jao.io/blog/geometrically-speaking.html geometric proofs, Kindergarten Quantum Mechanics
https://jao.io/blog/observatory.html Mozilla Observatory to check a website's security
https://jao.io/blog/simple-note-taking.html simple note taking

Just what it says. A 4 GB Rπ costs £8.63/month ≈ €9.57/month.

See also
https://askubuntu.com/questions/458427/who-reads-etc-default-keyboard
https://askubuntu.com/questions/1184746/how-to-make-caps-lock-an-additional-ctrl
https://askubuntu.com/questions/769462/request-for-a-guide-on-setting-up-apple-aluminium-keyboard-on-ubuntu-16-04

The easy-to-use, integrated, glanceable, and open web-based interface for your servers.
Cockpit makes GNU/Linux discoverable. See your server in a web browser and perform system tasks with a mouse. It’s easy to start containers, administer storage, configure networks, and inspect logs.

David Rosenthal's blog. Other interesting articles include
https://blog.dshr.org/2020/05/the-death-of-corporate-research-labs.html
https://blog.dshr.org/2020/06/informational-capitalism.html
https://blog.dshr.org/2020/03/more-on-failures-from-fast-2020.html

Different ways to swap CapsLock and Control.
See also https://askubuntu.com/questions/976996/add-custom-keyboard-layout?r=SearchResults

LambdaNative is an open-source (BSD licensed) cross-platform development environment written in Scheme (Gambit-C), supporting Android, iOS, BlackBerry 10, OS X, Linux, Windows, OpenBSD, and NetBSD. Some cross-compiler support for Raspberry Pi (Carlson-Minot) and OpenWrt (Sitara) also exists. See also https://www.lambdanative.org/

Wiki with explanations for Randall Munroe's comics https://xkcd.com/

ISA-L is a collection of optimized low-level functions targeting storage applications. ISA-L includes:
   Erasure codes - Fast block Reed-Solomon type erasure codes for any encode/decode matrix in GF(2^8).
   CRC - Fast implementations of cyclic redundancy check. Six different polynomials supported.
       iscsi32, ieee32, t10dif, ecma64, iso64, jones64.
   Raid - calculate and operate on XOR and P+Q parity found in common RAID implementations.
   Compression - Fast deflate-compatible data compression.
   De-compression - Fast inflate-compatible data compression.
BSD 3-Clause "New" or "Revised" License.
According to https://github.com/catid/cm256, ISA-L uses a O(N^3) Gaussian elimination solver for decoding. The CM256 decoder solves the linear system using a fast O(N^2) LDU-decomposition algorithm from "Pivoting and Backward Stability of Fast Algorithms for Solving Cauchy Linear Equations" (T. Boros, T. Kailath, V. Olshevsky), which was hand-optimized for memory accesses.
See also https://github.com/catid/leopard for a fast O(N log(N)) RS erasure decoder.