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 t
- http://www.dcc.uchile.cl/~rbaeza/handbook/hbook.html

Data Structures and Algorithms with Object-Oriented Design Patterns in C++
- A web text by Bruno R. Preiss of the University of Waterloo.
- http://www.brpreiss.com/books/opus4/html/book.html

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".
- http://www-cs-staff.stanford.edu/~knuth/taocp.html

Algorithms and Complexity
- A downloadable textbook by Herbert S. Wilf. Each chapter is available as compressed PostScript or PDF.
- http://www.cis.upenn.edu/~wilf/AlgComp.html

Introduction to the Theory of Computation
- Michael Sipser (PWS Publishing) Table of contents, errata.
- http://www-math.mit.edu/~sipser/book.html

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).
- http://www.nada.kth.se/~viggo/wwwcompendium/