freeform magic system for OSR RPGs

It is a freeform magic system for OSR games. It was created with Sharp Swords and Sinister Spells in mind but can be used, with minimun adjustment, with Black Sword Hack or with other 'roll-under' RPGs. It is still in development: any feedback is welcome. At this stage of development (untested prototype) it is free. EDIT#1: added Powerful Enemy rule notes and added conversion notes for D100 based games and 3d6 based games.EDIT#2: a friend of mine noticed a problem with remote-target casting. I fixed the problem with latest version (v0.5).