Algol-68, from 1968, was the most advance algorithmic computer language of its time, and this book was a bombshell which raised the standards for definition of a computer language. The language introduced early forms of metaprogramming (which evolved into templates or generics in the Algol family of languages. PL/1, Pascal, Modula, C, C++, Ada, Java, JScript, C#, etc. all have their form influenced by Algol, though some of the concepts (like access to nested stack scopes) were eventually discarded. van Wijngaarden was also a participant in the earlier Algol language. Algol 68 was considered to be very difficult to compile, although in modern terms fairly easy, so it did not have wide commercial use, but it was very influentional in language design. The book itself was educational since it explained precisely multiple new concepts like scope and meta-calculation which later became normal, but were new to most people at the time.