"Some of his most notable contributions were the vi editor, NFS, and csh. Joy's prowess as a computer programmer is legendary, with an oft-told anecdote that he wrote the vi editor in a weekend. Joy denies this assertion. Joy's accomplishments have been sometimes exaggerated; Eric Schmidt, CEO of Novell at the time, inaccurately reported during an interview in PBS's documentary Nerds 2.0.1 that Joy had personally rewritten the BSD kernel in a weekend."
"Joy was also a primary figure in the development of the SPARC microprocessors, the Java programming language, Jini / JavaSpaces and JXTA."
"BBN had a big contract to implement TCP/IP, but their stuff didn't work, and Joy's grad student stuff worked. So they had this big meeting and this grad student in a T-shirt shows up, and they said, "How did you do this?" And Bill said, "It's very simple — you read the protocol and write the code."
Love it. Reminds me of the Feynman Algorithm mentioned here on HN a few days ago. Regarding how Feynman came up with so much brilliant, groundbreaking work, that the steps he supposedly followed were:
1. Write down the problem.
2. Think real hard.
3. Write down the solution.