JAGS Revised is the revised version of the original, rules-heavy universal RPG. From the publisher's website:
"An award winning (Best Free Game Indie Awards 2006) universal table-top roleplaying system (click the FAQ if none of those words make any sense to you). JAGS Revised is the core rules book for the JAGS system. Find inside Skills, Traits, Stats, Combat, and Drama Rolls (which let you create your own in-depth rules for special campaign types)!"