The FastLED library for colored LED animation on Arduino
Blynk library for embedded hardware
Golang framework for robotics, drones, and the Internet of Things
ESP8266 framework for Homie, a lightweight MQTT convention
An open source ecosystem for IoT development
A Java VM for ARDUINO and other micros using the leJOS runtime.
Electronic design and programming tools suite like Eagle, MpLab
Re-imagining of Heisermann's classic Self-Programming Robot