Alternative firmware for ESP8266 and ESP32 based devices with easy configuration using webUI, OTA updates, automation using timers or rules, expandability and entirely local control over MQTT, HTTP…

Keyboard firmwares for Atmel AVR and Cortex-M

MQTT library for Arduino

Explicit state logic model checking tool -- 2002 winner of the ACM System Software Award.

KBC/Vortex Poker 2 Mechanical Keyboard Firmware hacking

Open firmware for Honeywell Rondostat HR20 and similar thermostats

DCamProf is a free and open-source command line tool for making camera profiles, and performing tasks related to camera profiles and profiling.