Adafruit: https://adafruit.github.io/arduino-board-index/package_adafruit_index.json Adafruit AVR Boards (Flora, Metro, Trinket, Pro Trinket, & Gemma) Adafruit SAMD Boards (Feather M0) TeeOnArdu USB MIDI support for Leonardo & Micro arcore USB MIDI support for Leonardo & Micro Adelino: https://raw.githubusercontent.com/neoautus/Adelino/762798ffd534436f3c28dc876ebc39256f0d5738/Platforms/Arduino/pac
