I see Daniel Bernstein hasn't been mentioned, but looking through his software, not many can match his track record of (seemingly) bug-free C code. In any case,

I see Daniel Bernstein hasn't been mentioned, but looking through his software, not many can match his track record of (seemingly) bug-free C code. In any case, he's a mathematician and it shows. Since learning about his patricia tree implementation (or rather, crit-bit tree), i've been using it in a lot of projects, and again, very clean and beautiful implementation of an efficient data structure. So yes, his work (among that of many others) has been a source of inspiration for me.