Elements of Abstract and Linear Algebra, by Edwin H. Connell:Full online book on abstract algebra with emphasis on linear algebra. Format: DVI, PDF, PS and gzipped-PS.
Arxiv: AC Commutative Algebra: Articles cover commutative rings, modules, ideals, homological algebra, computational aspects, invariant theory, connections to algebraic geometry and combinatorics.
Exploratory Galois Theory on the Web: By John Swallow (CUP, 2004). Supporting software in Maple and Mathematica.
Finite Rank Torsion Free Modules over Dedekind Domains: An unfinished book by Lee Lady.
The Book of Involutions: By M-A. Knus, A. Merkurjev, M. Rost, J-P. Tignol (Preface by J. Tits). AMS Colloquium Publications, Vol. 44 (1998). Table of contents, bibliography, index, errata, reviews.