Where does this term come from? What does it mean? What is its purpose? Why do I care? I don't, really. However, in a bored stupor I wrote this essay. Wait it isn't written yet. Ignore that.
Basically, "webmaster" refers to the person who owns and operates a site. This is a simple enough definition to grasp, but what if the webmaster is female? The feminine form of "master" is "mistress", so shouldn't I be using that to refer to myself? The blunt answer is no.
The long answer is that I like the way the word "master" looks compared to "mistress." Too, "mistress" can mean one of two things as well, neither of which are exactly what I'd like to be saying on a site linked to from the PokéGym. Go to dictionary.com if you don't know and are really interested.
So why does this matter? It doesn't, really. I was bored, I wrote this essay, and I'm a webmaster. I've seen people call themselves webmistresses and bug the girls and women who call themselves webmasters, and I don't care. I even wrote an essay to prove it. Boredom does strange things to me.
Oh, and kids, don't drink and derive. Math jokes are painful.