Harry Potter and the Methods of Rationality (HPMOR) is a Harry Potter fan fiction by Eliezer Yudkowsky, published on FanFiction.Net. It adapts the story of Harry Potter to explain complex concepts in cognitive science, philosophy, and the scientific method. Yudkowsky published HPMOR as a serial from February 28, 2010 to March 14, 2015, totaling 122 chapters and about 660,000 words. Wikipedia read it here or here
available in 100+ languages !
Edit : I say it is much better than (canon) Harry Potter.
Reading it right now for the second time ; it has big pros and big cons. it's a little sad no one is commenting in here aside from me. the pros :
here Harry Potter doesn't get pushed around like in the Canon version : he is equipped with science and logics. the cons :
it leaves the (hetero) reader hoping for love between Harry Potter and Hermione, instead the author chooses murky plots involving Draco Malfoy.