Bivius Solo RPG : A simple RPG and Solo System

Bivius Companion : Advanced rules for Bivius Solo RPG (updated version 1.1)

Nine Steps And A Bloody Heart : NSAABH is an investigative system for your Solo RPG (updated version 1.1)

Zathrum : A simple RPG Solo System that uses 1d20, compatible with every tabletop RPG (Bivius included of course)