Microlite20 is a free role-playing game containing character generation, combat and rules for magic, monsters and level advancement. The goal was to create as minimal a system as possible yet still retain enough d20 compliance to be able to use it without modification with published adventures.
Ultramicrolite20 is Microlite20 boiled down even further. It sacrifices d20 compliance for sheer minimalism. The rules themselves could fit on a single 3x5 record card.
Rank20 - d20 compatible, similar to ultramicrolite20, skill rank system drives all mechanics, magic system included. Can be run with a single d20. Released under the Creative Commons License by Rycanada (not originally a d20 derived game). Also available as in .rtf format.
Realms of Renown - “Realms of Renown is a fantasy game where you can be anything, a heroic dwarven warrior, wandering nomad, mysterious enchantress or marauding ogre mage. The action is fast, there are no complicated rules, and being the GM (Game Master) doesn’t leave you at wit’s end. In Realms of Renown the rules flow together allowing players to concentrate on adventuring and the GM on weaving a tale around the characters.” A d20 die, Ultramicrolite20 rooted, classless and leveless rpg game.
Quick20 - Quick20 is Mob United Media‘s light (7 pages of rules) OGL implementation that uses four attributes (Fortitude, Might, Reflex and Will), three classes (Warrior, Expert and Mystic) and 1d20 for all rolls. It includes freeform and memorized options for magic and is supported by multiple supplements for Asian-themed gaming, modern games and new character options. Familiar mechanics include the damage saving throw. You can find the line’s products here
Mini20 by Luigi takes much of Microlite20, adds in additional rules, classes, races and feats and presents it all in an excellent 24-page pdf. Recommended if you like the core rules ideas of Microlite20 (EL-based experience, the skill system, etc) and want something a little heavier without needed to add in House Rules yourself.
Lite20 by Ray Allen is Microlite20’s fat younger brother. Although I loved ML20’s rules lite feel, I needed more. I have combined the best parts of ML20, Basic Fantasy Role-Playing Game, and my own d20 house rules to create Lite20.
