Today is Don Knuth‘s 70th birthday. He is a giant in the field of computing science, and wrote TeX, the mathematical typesetting system that is used in the vast majority of scientific writing today.
A great many people are writing birthday tributes today (you can start here).
I do not usually have the mental energy to delve into his monumental (and still-incomplete) The Art of Computer Programming, but whenever I do, it’s always rewarding.
And his volume of commentaries on all the verses numbered 3:16 of the Bible, illustrated by the world’s greatest calligraphers and typographers, is delightful.