He pioneered the concept of literate programming. He is considered a famous programmer, known for his geek humor: as examples, he pays a finder's fee of $2.56 for any typos/mistakes discovered in his books because "256 pennies is one hexadecimal dollar". Version numbers of his TeX software approach pi, that is versions increment in the style 3, 3.1, 3.14 and so on, version numbers of Metafont approach e similarly; he once warned users of his software, "Beware of bugs in the above code; I have only proved it correct, not tried it." (source)
In 1968 he became a member of the faculty of Stanford University where he is currently Professor Emeritus of The Art of Computer Programming. He has received various awards including the Turing Award, the National Medal of Science, the John von Neumann Medal and the Kyoto Prize.
Knuth's hobbies include music, and specifically playing the organ. He has a pipe organ installed in his home. Knuth disclaims any particular talent in the instrument, however.
He is married to Jill Knuth, who published a book on liturgy. They have two children.
Knuth published his first "scientific" article in a school magazine 1957 under the title Potzebie System of Weights and Measures, part of which included defining the fundamental unit of length as the thickness of MAD Magazine #26, and the fundamental unit of force was named "whatmeworry." MAD Magazine bought the article and published it in the June 1957 issue.