What is a Homebrew RPG?

There I was enjoying a nice warm cup of java the other morning when the topic of Homebrew came up in conversation, as it often does. Some people were saying that they homebrewed their game by altering the rules of a popular RPG. After spewing some java out my nose, I let out an anguished cry. How can that be what you mean by Homebrew?! I asked incredulously. I was offered a few quips in reply, but nothing that was said assuaged my feeling that this really was not the right word for what they meant. So I'd like to clarify what I mean when I say "Homebrew" in relation to RPGs.

I started GMing in 1978 with my first World, and first rules system, both going by the name of Elthos RPG. The rules I created after a skim-reading of "Men & Magic", the first volume of the original three (and highly magical) D&D booklets. My rules system had a couple of design goals. One was to eliminate the odd zig-zag math used by OD&D. I wanted even charts with easy to remember values. The second goal was to centralize (what later became known as) Conflict Resolution. I created one centralized chart that pits Difficulty Level vs Skill Level for all possible skills. In this way I wanted to avoid the need for endless additional charts for all of the doodads I might want to add to Elthos over time. The goal was to create a Homebrew system that I could rely on to only change in ways that make sense for me as the GM, and to avoid being tethered to rules systems that would inevitably alter the nature of the world itself. Thus I would be able to maintain my world for a long time exactly the way I envision it, and my world's history would not be subject to the whims of TSR's rules editions over time.

These two design decisions resulted in a system that has served me well for 40+ years.

The second leg of Homebrew is the Setting. My world is my own creation. Sure, of course I borrow ideas from many sources, historical and literary, but there is no tether that is tied to any of them. As such my world's only cannon is it's own history. The reason I wanted it this way is to keep my players from being "in the know" about things in the world that would be much more entertaining as surprises, than facts they encountered elsewhere. To me this is much more fun for everyone.

So for me, the word "Homebrew" suggests a creation from more or less whole cloth by the Gamemaster. Filled with surprises and idiosyncrasies that make sense to their creators, and are not beholden or tied to some corporate behemoth. It is the freedom and versatility of Homebrew that attracts my ardor. I think from a creativity perspective Homebrew is definitely the way to go.

As for what I think the correct word for what was mentioned by my buddy online the other morning is "House Rule". Homebrew and House Rule are two different things. There is some overlap, of course, but they are really quite distinct in my mind.

What do you think? Am I right about this? What's your definition of Homebrew?