Paul McJones alerts us that the ACM posted PDF versions of some books in its Classic Books Series, which are available to anyone who creates a free ACM Web Account.

Among the currently available books, LtU readers are likely to be particularly interested in Hoare and Jones's Essays in computing science, Adele Goldberg and David Robson's Smalltalk-80: the language and its implementation, and Dahl, Dijkstra, and Hoare's Structured programming.

Long time readers will also know that I highly recommend Papert's Mindstorms: children, computers, and powerful ideas to anyone interested with the effect computers might have on education. Papert's Logo remains to this day the best children oriented programming language, but even if you disagree with me about this, his book is a must read.