When you write about Donald Knuth, it's natural to sound scriptural. For nearly 40 years, the now-retired Stanford University professor has been writing the gospel of computer science, an epic called The Art of Computer Programming. The first three volumes already constitute the Good Book for advanced software devotees, selling a million copies around the world in a dozen languages. His approach to code permeates the software culture.

And lo, interrupting his calling for nine years, Donald Knuth wandered the wilderness of computer typography, creating a program that has become the Word in digital typesetting for scientific publishing. He called his software TeX, and offered it to all believers, rejecting the attempt by one tribe (Xerox) to assert ownership over its mathematical formulas. "Mathematics belongs to God," he declared. But Knuth's God is not above tricks on the faithful. In his TeX guide, The TeXbook, he writes that it "doesn't always tell the truth" because the "technique of deliberate lying will actually make it easier for you to learn the ideas."