This makes a character's proficiency in the various spell schools increase their maximum magicka in relation to intelligence. Mastering the six spell schools will increase maximum magicka by x3.0 intelligence. This in effect puts less emphasis on racial and birthsign choices for spellcasting characters, allowing more diversity with spellcasters.
Download at Morrowind Nexus: http://morrowind.nexusmods.com/mods/42269