I don't have it with me at work, but the basic idea is a spell point system where you build the different components of the spell you want to cast. You then make a DC (skill?) roll to cast it successfully. The latter stops the NOVA effect, since that would set to high the DC for a spell that used all your spell points up for the day.
In addition, there is a fatigue rule - every spell you cast makes further spells harder to cast that day. This stops the "millions of mini-spells" effect to some degree.
Some people really really like it, and even use it apart from the rest of the rules.