...and for those on HN who are self-taught and aren't aware of the history of computer science, ALGOL is the foundation of imperative programming and inspires just about every imperative language today.

Crucially, this means C and C++, which means that Dijkstra's work is part of the foundation for most operating systems and low-level code in the world - indeed most software systems period, since the vast majority of these are somehow based on C.