“This manual is a bit different. It was written entirely by unpaid volunteers, all of whom are keen to share their expertise and enthusiasm for computing with as many people as possible. What all of these contributors have in common, apart from a youth spent mainly indoors in front of ZX Spectrums and Commodore 64s, is that they’re all members of the organisation Computing at School (CAS). To find out more about CAS and its work promoting the teaching of computer science, head over to http://www.computingatschool.org.uk”