Software-defined radios - you can do absolutely insane things with these. Listen to multiple radio stations as once, listen to ham radio, capture live images of the earth from geostationary satellites, watch live airplane traffic, listen to maritime radio, ...try to listen to signals using the moon as a reflector.., detect GPS jammers..., sync 5 of them to the same clock source and use them as a passive radar array to track objects' movements through walls..... use them for backyard radio astronomy to detect the ion trails due to the hydrogen emission line of blazing meteorites.... this shit is cheap too the most common basic model is like only 20 bucks.

Haskell

Jax / Awkward Array

Topological Data Analysis

Cocalc

CLIP

gitpod / vscodeweb / github codespaces

CodeQL

DDSP

mathlib

neovim

language-server-protocol

adafruit feather m0

rr

linear logic

tmux