Quick explanation about the files here:
afl-analyze.c - afl-analyze binary toolafl-as.c - afl-as binary toolafl-gotcpu.c - afl-gotcpu binary toolafl-showmap.c - afl-showmap binary toolafl-tmin.c - afl-tmin binary toolafl-fuzz.c - afl-fuzz binary tool (just main() and usage())afl-fuzz-bitmap.c - afl-fuzz bitmap handlingafl-fuzz-extras.c - afl-fuzz the extra function callsafl-fuzz-state.c - afl-fuzz state and globalsafl-fuzz-init.c - afl-fuzz initializationafl-fuzz-misc.c - afl-fuzz misc functionsafl-fuzz-one.c - afl-fuzz fuzzer_one big loop, this is where the mutation is happeningafl-fuzz-python.c - afl-fuzz the python mutator extensionafl-fuzz-queue.c - afl-fuzz handling the queueafl-fuzz-run.c - afl-fuzz running the targetafl-fuzz-stats.c - afl-fuzz writing the statistics fileafl-gcc.c - afl-gcc binary tool (deprecated)afl-common.c - common functions, used by afl-analyze, afl-fuzz, afl-showmap and afl-tminafl-forkserver.c - forkserver implementation, used by afl-fuzz and afl-tmin afl-sharedmem.c - sharedmem implementation, used by afl-fuzz and afl-tmin