The SAMD21 M0-Mini represents a powerful, 32-bit extension of the Arduino UNO platform, but in a small size like Micro or Nano. The board is powered by Atmel’s SAMD21 MCU, featuring a 32-bit ARM Cortex® M0 core.
Compatible with Arduino Zero and Arduino M0.
The SAMD21 M0-Mini board expands the family by providing increased performance, enabling a variety of project opportunities for devices, and acts as a great educational tool for learning about 32-bit application development.
One of its most important features is Atmel’s Embedded Debugger (EDBG), which provides a full debug interface without the need for additional hardware, significantly increasing the ease-of-use for software debugging. EDBG also supports a virtual COM port that can be used for device and bootloader programming.

MicroPython on SAMD21 M0 MINI:
This board is a compact and powerful electronics development board that can run MicroPython.
It connects to your PC over USB, giving you a USB flash drive on which to save your Python scripts.
With the MicroPython pyboard you gain a low-level Python operating system that you are able to use to control plenty of different electronics projects.
MicroPython is a complete rewrite of the Python (version 3.4) programming language so that it fits and runs on a microcontroller.
It includes many optimizations so that it runs efficiently and uses very little RAM.
Additionally, MicroPython runs bare-metal on the board, and essentially gives you a Python operating system.

Did you know that you can code your SAMD21 M0 MINI using Blocks, JavaScript, and Microsoft MakeCode.
Microsoft MakeCode is a free, open source platform for creating engaging computer science learning experiences that support a progression path into real-world programming.
Try with Microsoft MakeCode Here. 

Tech Specs:
Microcontroller : 32-bit ARM Cortex® M0
Power: Through USB or 6-9V input
Digital I/O Pins: 25GPIO
Onboard LED: On D13
Flash Memory: 256KB 
SRAM:  32KB
Clock Speed: 48 MHz
Interfaces: UART, I2C, SPI, ADC and DAC
USB Interface: Micro USB(Native) Power and Serial comms
It can also act HID unit, like a keyboard, mouse, joystick or MIDI device as well.