libc.c: Defines various standard libc functions to reduce the dependency on libc: string functions, formatting, environment, and other runtime utility functions.options.c: Allocator options, environment-based configuration, and diagnostic output.random.c: Random number generation, seeding, and splitting of random streams.stats.c: Allocation statistics, aggregation, reporting, and process information.threadlocal.c: Dynamically allocated thread-local keys and per-thread value storage.