Jon Claerbout suggested the separation of solvers and applications using object orientation. Dave Nichols guided me among half-a-dozen other programmers in the implementation of CLOP, a first implementation of Jon's idea. Independently, Dave Nichols and Lester Dye as well as Mark Gockenbach and Bill Symes developed a more rigorous framework that based its class design on mathematical entities. I later helped Lester and Mark to unite the two frameworks into the Hilbert Class Library. Frustrated by HCL's inability to attract programmers among our laboratory's researchers, Joel Schroeder and I designed a Java library that rivals HCL but takes advantage of Java's simpler object-oriented features and its comprehensive library support. Thanks to all of you. It was great fun!