A credit-card-sized low-cost computer designed to help teach children to code has gone on sale in Britain, its developers say.

The Raspberry Pi is a bare-bones computer created by volunteers mostly drawn from academia and the British tech industry hope the machines could help reverse a lack of programming skills in the country.

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

Sold uncased without keyboard or monitor, the $35 Pi has drawn interest from educators and enthusiasts.

The launch of the Pi comes as the Department for Education is considering changes to the teaching of computing in schools with the goal of greater emphasis on skills like programming.

"Initiatives like the Raspberry Pi scheme will give children the opportunity to learn the fundamentals of programming," Secretary of State for Education Michael Gove said.

The Raspberry Pi Foundation says it has already produced thousands of the machines using a Chinese manufacturer.