Just One Sword is a complete, solo-first, standalone game that does not require anything else to play. It has all the rules, procedures, tools, Bestiary, oracles, etc. necessary to make the game run. It is not a supplement or toolkit.
Just One Torch is a toolkit for taking an existing OSR RPG (Shadowdark, OSE, BFRPG, Whitebox FMAG, etc.) and converting it into a solo game. It is primarily oracles, a few procedure changes, and some recommended adjustments to make your game of choice more survivable. It is not a full game and will require a game of your choice to run.