It is an open hardware product fully compatible with the Arduino Yun sketches: use your existing Arduino Leonardo and make it wireless, or match it with an Arduino Mega 2560, Arduino Due, Arduino Zero. Easily connect more storage, a dynamic web server, a webcam or an audio device.
The shield runs OpenWrt-Yun an embedded Linux distribution based on OpenWRT created by the Arduino team. Also it is featuring a new boot loader called Caraboot. The new firmware image can be read from the USB flash drive.