by Bjarne Stroustrup
Describe all of C++ in 100 pages (or less). Don't just describe the language, include the standard library. Don't use "white lies" to simplify. Describe the major programming styles and techniques. Give rationale. Don't forget about concurrency. And, oh, by the way, make it readable to programmers (do not require a PhD).
That was the task I set myself when I decided to write the "Tour of C++" for TC++PL4. I suspect that succeeding perfectly is beyond me, but at least I met the first criteria: The tour is currently 98 pages, and shrinking.This last, part 4, of the tour presents concurrency and some of the newer standard-library facilities.
See the whole Tour here.