James S Milne is a professor of Mathematics at the University of Michigan, Ann Arbor. He mainly works in arithmetic geometry. He has written a few books on the subject as well as some related fields. He hails from New Zealand.
His personal website can be found here.
His site has the most awesome notes on several topics in Algebra, including Group Theory, Ring Theory, Fields and Galois Theory, Algebraic Number Theory, Algebraic Geometry, etc. Here’s a link. I read a few pages of his ANT notes in my first year and I loved it. I am thinking of completing that in the coming summer.
For more information on him, check Wikipedia.