Reduce was written by William Carlson in early June 1991, and updated through early 1992 by Richard Ketcham (and a bit by Cambria Johnson (now Denison). This operated on a 2D data set and was coded in Pascal for the Mac (System 7?). When processing of 3D data sets was required, Reduce3D was forked off, and the 2D version renamed to Reduce2D. This still exists someplace in Austin, TX, but probably hasn't been used by anyone since 1993 or so.
Reduce3D was writted by Richard Ketcham in late 1992, and versions through 2.0.0 are by Rich. This was also coded in Pascal for the Mac. Developement was taken over in 1995 by David Hirsch, and the program was rewritten in C++ using the CodeWarrior PowerPlant classes, and substantially expanded over the period from 1995-2000. It languished until 2007, when it was reorganized and ported to the XCode environment, removing all PowerPlant and incorporating Objective-C for much of the user interface. All development has been performed under the advisement of William Carlson.