Raspberry Pi computer
A credit card sized low cost Raspberry Pi computer.

The Raspberry Pi, a credit card-sized, low-cost computer, priced at £22 and designed to help teach code to children, has gone on sale from Wednesday.

So popular was the mini-computer that reportedly the Web site of one of the product's online retailer - Leeds-based Premier Farnell - crashed, following its launch.

The computer took nearly six years to design and develop and, according to the BBC, the final device has inputs from volunteers from the world of academia and the UK tech industry.

"It has been six years in the making; the number of things that had to go right for this to happen is enormous. I couldn't be more pleased," Eben Upton of the Raspberry Pi Foundation is quoted as saying by the BBC.

The BBC report notes the Pi is sold uncased, without a keyboard or a monitor and a cheaper £16 version will be sold later in the year.

The single board computer runs on a 700MHz ARM processor and has 256MB of RAM, according to Techradar.com.

Apparently the primary reason why the computer was developed was to help familiarise school children with the idea of computer programming.

The device, according to The Guardian, has a USB port for a keyboard, an Ethernet port, a SD card slot and a HDMI port for video output.