On: Ask HN: What are the “best” codebases that you've ...

[m463]

sel4 microkernel is pretty cool.

"The world's first operating-system kernel with an end-to-end proof of implementation correctness and security enforcement is available as open source."

for instance, look at strnlen:

  word_t strnlen(const char *s, word_t maxlen)
  {
      word_t len;
      for (len = 0; len < maxlen && s[len]; len++);
      return len;
  }

http://sel4.systems/

https://github.com/seL4/seL4