What kind of philosopher was Socrates?

Perhaps the most famous Western philosopher of all, Socrates bears the curious distinction of being famous while never having personally written down (or otherwise recorded) his "philosophy." At the same time, judging by the many writings about Socrates that have been preserved through the centuries, it is clear that he was above all a "moral philosopher"; that is, he was mostly concerned with answering whatever questions would help human beings -- and himself -- to become really and truly good.