There have been a number of ventures that have tried to produce a cheap computer such as a laptop and a tablet but which never materialised at these price points. Nothing comes close to the Raspberry Pi in terms of affordability, which is even more important in the current economic climate. Producing a PC capable of running Linux, Quake III-quality games, and 1080p video is worthy of praise.
There are two editions of the Raspberry Pi, the Model B which we have, and the Model A which is identical except that it loses the ethernet port and one of the USB slots. The labels Model A and Model B are in deference to the BBC Micros of the early 1980s, computers also with an emphasis on education. Both models pack everything a system needs into a single-board.