TinyPICO
TinyPICO is the world's smallest, fully-featured ESP32 development board in a package smaller than your thumb!
TOMU
Tomu is a programmable computer that fits inside a USB port. It is user-programmable, has two buttons and two LEDs.
Teensy 4.1
Teensy 4.1 features the fastest micocontroller and an expanded set of powerful peripherals in a 2.4 by 0.7 inch form factor.

Teensy 4.0 is the latest Teensy, offering the fastest microcontroller and powerful peripherals in the Teensy 1.4 by 0.7 inch form factor.

Teensy 4.0 is the latest Teensy, offering the fastest microcontroller and powerful peripherals in the Teensy 1.4 by 0.7 inch form factor.

This adaptor board connects Teensy 3.2 - Teensy 4.1 to thousands of LEDs using the OctoWS2811 Library.