And a Basic that was adopted by a number of other platforms, and is still useable today. It was a good intro to structured programming, and it had an inline assembler you could call from within your Basic program, including passing variables to the assembly subroutine. We used Model As and Bs at our school, and we had a B at home. I got my first taste of programming on those puppies.

As usual, the wikipedia article is a good place to start.

There's a guy been staying here recently who's a dev for the One Laptop Per Child program. We got to discussing the similarities between that and the BBC Computer Literacy Project which spawned the Beeb series of computers.