Step #91 in the Expanded Vanilla list
Magicka Based Skill Progression - ncgdMW Compatibility Version, Magicka Based Skill Progression - Better Sounds/ncgdMW Compatible
HotFusion4 - edits by Greywander, Joao Almeida, and p4r4digm
Featured In Mod Lists:
This mod makes magical skill progression based on the amount of magicka used, instead of number of spells cast.
The description contains extensive notes about how the mod works and differs from other versions. Please take the time to read through it, in particular the part labeled "Opinions Addendum, updated with play-testing", where the author talks about growth rates and what works for whom.