Executable Archaeology: Reanimating the Heuristic Compiler (1961) and KBEmacs (1984)

The study reconstructs two historical systems that embodied explicit ideas about how people program. Herbert Simon’s Heuristic Compiler, developed in 1961, treated programming as problem-solving: it used means-ends analysis, associated with Simon’s General Problem Solver, to select steps toward a desired program. KBEmacs, created in 1984 by MIT’s Programmer’s Apprentice project, reflected a different emphasis: expert programmers build software by recognizing and combining familiar patterns, called “clichés.” Its users assembled programs through a controlled, English-like command language. The researchers use “executable archaeology” - recovering and running original software - to examine these theories in practice rather than relying only on historical descriptions.

The team reports that the reanimated Heuristic Compiler generates the same compiled code shown in Simon’s 1963 paper, while KBEmacs reproduces the square-root sequence in its December 1984 self-test. Comparing them reveals a closer kinship than their contrasting designs suggest: the Heuristic Compiler also adapts existing routines, and Simon later acknowledged that effective search depends on substantial programming knowledge. The project’s reconstruction work itself has a modern twist: the researchers used Claude Code, an AI-assisted programming tool, alongside existing software. They argue that today’s more capable coding assistants lack the explicit, executable theories of programming that these earlier systems made visible, making the systems useful both as historical artifacts and as prompts for thinking about current AI.