Abstract Algebra
- http://www.jmilne.org/math/CourseNotes/
- Course notes by J.S. Milne. Topics covered are group, fields and Galois, algebraic number, class field theories. Other areas discussed are modular functions and forms, elliptic curves, algebraic geometry, Etale Cohomology, and Abelian varieties. In HTML, PDF, PostScript and DVI formats.
Abstract Algebra
- http://www.math.uiuc.edu/~r-ash/
- Three books by Robert B. Ash (chapters in PDF): Abstract Algebra: The Basic Graduate Year, A Course In Algebraic Number Theory, and A Course In Commutative Algebra.
Algebra notes
- http://www.math.uga.edu/%7eroy/
- Roy Smith's course notes in linear algebra, elementary abstract algebra, basic graduate algebra, and a survey of the Riemann-Roch theorem from Riemann to Hirzebruch.