This specification allows a 3rd party vendor/maintainer to add support for new boards inside the Arduino IDE by providing a file to unzip into the hardware folder of Arduino's sketchbook folder.
Eleven sensors + BLE + WiFi + OLED
UDOO is a very powerful board based on dual or quad core ARM cortex-A9 CPU with great performance both on Android and Linux OS, and a dedicated ARM processor for the GPIO
SquareWear 2.0 is an open-source, Arduino-based wearable microcontroller board.
The BareDuino Nano is the world’s smallest Arduino compatible board.
A tiny Wi-Fi development board. Arduino + Wi-Fi + ARM Cortex M3 + wireless programming + REST API = awesome.
The R2Duino is a fully assembled USB stick sized Arduino clone based on the ATmega328P. It has the same functionality as the Arduino Nano 3.0, but comes in a different package.
StickDuino - USB Stick Sized Arduino Clone
SdFat is an Arduino library that supports FAT16 and FAT32 file systems on standard and high capacity SD cards.