A Compendium of NP Optimization Problems
By P. Crescenzi and V. Kann; KTH Stockholm. A continuously updated version of the appendix from the book "Complexity and Approximation" (Springer, 1999).
Algorithms and Complexity
A downloadable textbook by Herbert S. Wilf. Each chapter is available as compressed PostScript or PDF.
Branching Programs and Binary Decision Diagrams
By Ingo Wegener (SIAM, 2000). Errata, solutions to exercises, updates on open problems.
Data Structures and Algorithms with Object-Oriente
A web text by Bruno R. Preiss of the University of Waterloo.
Handbook of Algorithms and Data Structures
By Gaston H. Gonnet and Ricardo Baeza-Yates. The preface, table of contents, index and all source code of this handbook. The main goal is to make available through Internet the source code of many algorithms (in C and/or Pascal) that have been already tested.
Introduction to Circuit Complexity: A Uniform Appr
By Heribert Vollmer (Springer, 1999). Excerpts, errata, bibliography in BibTeX format.
Introduction to the Theory of Computation
Michael Sipser (PWS Publishing) Table of contents, errata.
The Art of Computer Programming (TAOCP)
By Donald E. Knuth. Bibliographic details of the published volumes (1-3, various editions and translations) and on-line beta versions of parts of volume 4, "Combinatorial Algorithms".