AT90USB1286 development board

AT90USB1286 and smaller alternatives development board. It was designed to provide larger amount of IO pins when UNO and similar run out of pins and memory. Packaged in breadboard friendly configuration.  The board can is also known as Teensy++ thus the boot loader can be flashed to respond as it or other boot loaders available on internet.
It contains 5v0 and 3v3 regulators to provide higher current for off board logic.