MicroPython - a lean and efficient Python implementation for microcontrollers and constrained systems

Lua based interactive firmware for ESP8266, ESP8285 and ESP32

Open Source Soldering Iron firmware

Free (libre) font editor for Windows, Mac OS X and GNU+Linux

mGBA Game Boy Advance Emulator

Nintendo 3DS "Custom Firmware"

A full functional WiFi Repeater (correctly: a WiFi NAT Router)

Arduino and PlatformIO IDE compatible TFT library optimised for the Raspberry Pi Pico (RP2040), STM32, ESP8266 and ESP32 that supports different driver chips

In application debugger for ARM Cortex microcontrollers.

Adafruit GFX graphics core Arduino library, this is the 'core' class that all our other graphics libraries derive from

Bring enhanced HID functions to your Arduino!

Open Source scanning laser rangefinder

Go bindings for raylib, a simple and easy-to-use library to enjoy videogames programming.

ATTiny usb bootloader with a strong emphasis on bootloader compactness.

code powering the comma.ai panda

Library for Switch Homebrew

Programs and scripts to display "inline" in Adafruit Learning System guides

Light weight library to control WS2811/WS2812 based LEDS and LED Strings for 8-Bit AVR microcontrollers.

MicroPython for ESP32 with psRAM support

ATtiny microcontroller support for the Arduino IDE

Adafruit code for the Nordic nRF52 BLE SoC on Arduino

Proof-of-concept NES emulator for the ESP32

USB-enabled bootloaders for the nRF52 BLE SoC chips

Arduino Core for SAMD21 CPU

Arduino Library for AES Encryption (source based on avr-crypto-lib)

CUPS filter for thermal printers as Zjiang ZJ-58, XPrinter XP-58, etc

3DS / Wii U / Switch master key generator

Optimized ILI9341 TFT Library

USB Mass Storage bootloader (based on UF2) for SAMD21 and SAMD51

Framework for building Arm Cortex-M "FLM" style flash programming algorithms.