The Raspberry Pi is a small computer with the form factor of a match box, capable of running a fully fledged Operative System (a port of Debian Linux named Raspbian is available for download).

The Model B+, released in July 2014, provides the following features:

• 4 USB ports
• HDMI output
• Ethernet connectivity
• 40 programmable General Purpose Input/Output (GPIO) pins
• Full HD video decoding

The Model B+ replaced the Model B, characterized by only 2 USB ports and 26 GPIO pins. The code and pin-out adopted within the WAN4RP projects ensures backwards compatibility with Model B.

You can find *a lot* more information on the Raspberry Pi on its website.