A pattern of language evolution

In 1992 when we completed our first draft of the History of Programming Languages II paper, The Evolution of Lisp [1], it included sections on a theory or model of how complex language families like Lisp grew and evolved, and in particular, how and when diversity would bloom and consolidation would prune. The historian who worked with all the HOPL II authors, Michael S. Mahoney, did not believe our theory was substantiated properly, so he recommended removing the material and sticking with the narrative of Lisp's evolution. We stopped working on those sections, but they remained in the original text sources but removed with conditionals. Copyright © 2008 ACM.