Calao Systems was a French company producing small Linux-based computers, roughly the size of a USB key. The company has gone bankrupt in April 2016. Devices use an Atmel or a Nomadik processor (based on ARM architecture) and usually offer about 128MB of RAM (up to 1GB for the most advanced models). The operating system is placed in the 128MB - 1GB non volatile memory. Devices also have a connector to which small expansion boards can be fitted on the top of the main board. There are expansion boards for wireless, motion sensors, Bluetooth and so on.