Pinguino is an Arduino-compatible open source hardware electronics prototyping platform. It supports different 8- and 32-bit microcontrollers, all with built-in USB module
New library : I2C 16-bit I/O expander #Pinguino can now drive Microchip MCP23O17 / MCP23S17 16-bit input/output port expanders with i2c interface, interrupt output and cascadable for up to 8 devices on one bus.
Pinguino Software is an Integrated Development Environement (IDE) which gives everyone the ability to write, compile and upload programs on a Pinguino board.
Pinguino comes with a USB Bootloader. This small program running inside the microcontroller is responsible for transferring your application from your PC to the microcontroller memory and handing over the control to this program afterwards.