KNAVE is a rules toolkit created by Ben Milton for running old school fantasy RPGs without classes. Adding, subtracting and modifying rules is both expected and encouraged.
DriveThruRPG - https://www.drivethrurpg.com/product/250888/Knave
Questing Beast - https://questingbeast.itch.io/
- Attack and damage rolls from character inventory, with target support
- All roll tables, spells, items, and rules from KNAVE are included in compendiums
- Automatic inventory slot counting
- Macro for initiative