Dave optimizes LinearProgramming codes.
When I was first programming in Smalltalk I mentioned to Dave that I was now writing the equivalent of pages of FORTRAN in a couple of lines. He was doing the opposite: writing pages and pages for the equivalent of a couple of lines of FORTRAN. Dave was coding for the Cray XMP, the fastest computer in the world. The patterns he used were not unlike those used by the best SmalltalkImplementers.
Dave taught me to program in CompassAssembler? for the CDC-6000. His son, DonDodson, has offered his own improvements to Dave's LinearShuffle.