Niels Henrik Abel: A Short but Influential Life — Biography by Håkon Fenstad; from the website of the University of Oslo. 

Niels Henrik Abel — Biography from the Department of Mathematics, University of Kansas. 

Abel, Niels — Biography on the website of Seton Hall University, New Jersey.

Niels Henrik Abel — Article by J. J. O'Connor and E.F. Robertson on the website of the School of Mathematics and Statistics at the University of St. Andrews, Scotland.

Niels Henrik Abel — Biographical sketch on the website of the Mathematical Institute of the Technical University of Budapest.

Abel, Niels Henrik — From Eric's Treasure Troves of Science website. The article is unintelligible to persons lacking knowledge of mathematical theory.

The Life of Niels Abel — A student effort on the website of Norfolk Academy, a secondary school in Norfolk, Va.

Niels Abel — Brief biography by Fred Worth in slide show format. On the website of Henderson State University, Ark.