d20 Lite, this game uses the d20 system but without skills in a way. It uses whats called knacks, skills you get as you try doing certain things many times between levels, when you say try and ride a horse many times, when you advance to the next level, you can add it as a knack and have an easier time at riding horses. It kinda reminds me of the old 2e AD&D amalgamated with the 3.0 D&D d20 system somewhat. It makes it quite easy to use Monster Manuals from D&D 3.x and modules with PFRPG.
Liked: A simplified d20 version and open gaming system.
Disliked: Not much, it could use more monster pictures, this seems to be the way most OGL books are anymore, lack of monster art.
Overall its a nice workable set of rules based on the d20 OGL and some old school rpg systems, I recommend them to anyone looking for a game without feats and tons of skills.