Jacquard looms, then and now, punched cards
Picture of difference engine
Picture of part of the mill of the analytical engine
Turing, the Turing machine, and the idea of a universal computer
Dictionary of programming languages (with many examples in different languages)
Standard ML of New Jersey (compiler, tutorials, etc.)
Jeffrey Ullman, Elements of ML Programming (2nd edition), Prentice-Hall, 1998.
Grammars
EBNF for C (from Kernighan/Ritchie)
Imperative Programming
Go to statement considered harmful (influential letter in the ACM communications by Edsger Dijkstra)
"GOTO considered harmful" considered harmful (letter in the ACM, reply to Dijkstra causing even more of a stir)