I thought of a cute problem: what is the smallest (size) ./a.out binary I can create? Here are some rules the program should follow: ./a.out must run successfully. $? must deterministically be 0. The binary must be produced by GCC only; no post-processing with objcopy, hex editors, or manual patching. We begin with the simplest program possible: // compiled with gcc empty.c int main() { return 0; } This gives us a file size of 15816 bytes (from stat). Not too shabby, but we will need four RAM used in the Apollo guidance computer to fit our binary that does nothing.