It started with my perceiving a necessity to revamp the original classes to better suit my vision for the Mutant Earth; next I was turned on to several among the befuddling kaleidoscope of game systems that seemed to better match that vision than the swords and sorcery oriented ancestor of them all (from Risus to Ghostbusters Int'l; Two-Fisted Tales; most especially Cartoon Action Hour, which I was thrilled to learn was revamped and streamlined as Cartoon Action Hour Season Two and which I encourage all of you to buy; Jeff pointed me to Arduin and its Techno class, and his write-up of it got me hungry for T&T); and all that left me gaping at the wilderness of work, the endless hours of pruning and planting, required before I'd even have a game to play.
Not to mention the money I'd have to spend (or figure out how torrents work, I suppose).
But I remembered that the inspiration for my hogwild fever dream of a campaign galaxy was a line in one of Sham's posts about the OD&D rules in which he lamented the missed opportunity to 'make D&D D&D,' by which he meant, I think making D&D encompass any wild flight of fancy you please. (I have no faith that I remember any of that correctly, so please right my errors in the comments.)
And lo! The correct and answer returned to me: the game I want is the one I don't have to spend money on. Thus, it's OD&D. The most valuable lesson I've learned since I discovered Ye Olde Schoole Renaissance, is that I need never spend money on gaming supplements again (though I will, as a gesture of gratitude to Fight On!, Jim Raggi, Geoffrey McKinney, Goblinoid Games, Mythmere Games, Brave Halfling Publishing, Elf Lair Games, and the rest of our friends).
I need never spend money on game supplements again. The game I want will come from my head. God, how I wish I had realized that before I bought EVERY BOOK WotC PUBLISHED FOR 3.5.
Where was I going with this?
The Mutant Earth will run on OD&D, right, with the addition of a Technician class as well as Carcosan Sorcerers (though with slightly less ickiness--this is children's programming, after all).
Meanwhile, though I know I can find it myself with the slightest effort, I'll ask any of my readers to help me out with locating a reasonable replacement for Outdoor Survival, seeing as how it's integral to OD&D--all the more so in my case, as the Mutant Earth itself is all wilderness. (At least on this hemisphere. . . shh! Don't tell my players!)