Teensy USB Development Board
Watterott: Teensy v3.2 USB Board – MK20DX256 ARM Cortex-M4
adafruit: Teensy 3.2 + header
sparkfun: Teensy 3.2
About Erich Styger
Hacking the Teensy V3.1 for SWD Debugging
Constructing a Classroom IDE with Eclipse for ARM
JTag on Teensy