A successful tool is one that was used to do something undreamt of by its author.

In 2002 he joined MathWorks to contribute to the MATLAB programming language. In 1986 he went to Silicon Valley where he was part of a half dozen or so startup companies including Transmeta.

Johnson served on the USENIX board for ten years four of those as president and is now the USENIX representative to the Computing Research Association. Johnson's famous epigram is often quoted: "Using TSO is like kicking a dead whale down the beach".