tl;dr: Austin Henley built a Python-like interpreter in exactly 1024 bytes of C, supporting features like integer variables, arithmetic, if/else, while and for loops, function definitions, and recursion, enough to run FizzBuzz. The interpreter skips tokenization/AST/bytecode entirely, executing directly via recursive descent and handling loops by rewinding and reparsing the source. Heavy code-golfing tricks (C89 implicit int, ASCII literals, globals as temps, bitwise ops) were needed to hit the size limit, shrinking a ~4800-byte readable version down to 1024.