East Side, West Side - Lecture notes by Herbert S. Wilf on generating combinatorial objects and Maple.

Algebraic Combinatorics via Finite Group Actions - A hypertext by A. Betten, H. Fripertinger and A. Kerber.

The Cutting Sticks Problem - An interesting unsolved combinatorial problem.

Golomb Rulers - The Search For 20 and 21! - Web Site devoted to the search for Golomb Rulers of 20 and 21 marks.

World Combinatorics Exchange - Including The Electronic Journal of Combinatorics. Databases, researchers' home pages, events and other resources.

CATS: Combinatorial Algorithms Test Sets - To facilitate experimental research by standardizing common benchmarks, providing a mechanism for their evolution, and making them easily accessible and usable; and identifying significant open questions in the design of good test sets and the assessment of performance of existing algorithms. To facilitate algorithm selection for applications by characterizing subproblems and the behavior of competitive algorithms on these subproblems. To encourage the development of high-quality implementations of advanced algorithms and data structures.

CADCOM - Committee for the Advancement of Discrete and Combinatorial Mathematics.

British Combinatorial Committee - The British Combinatorial Committee is a body which works for the support of combinatorial and discrete mathematics in the United Kingdom.

Combinatorics Problems - Combinatorics problems selected from math olympiads.

Combinatorists of New England - Information about meetings of the society.

The Combinatorics Net - Very comprehensive site.

ArXiv Front: CO Combinatorics - Combinatorics section of the mathematics e-print arXiv.

SIAM Activity Group on Discrete Mathematics - Focuses on combinatorics, graph theory, cryptography, discrete optimization, mathematical programming, coding theory, information theory, game theory, and theoretical computer science, including algorithms, complexity, circuit design, robotics, and parallel processing.

Enumeration of the Binary Trees - A note on Catalan numbers.

Handbook of Combinatorial Designs - Home page for The CRC Handbook of Combinatorial Designs (ISBN: 0-8493-8948-8). Contains errata, new results.

Discrete Optimization: Theory and Applications - DONET is an EC network

The Combinatorial Object Server - Select a type of combinatorial object from a wide range, together with specific parameter values, and COS will return to you a list of all such objects.

Amazing Mathematical Object Factory - Background information and generators for several basic combinatorial objects, with an educational slant.

Phalanstère - Research into the relations between algebra and combinatorics.

Ted Spence's Home Page - Classification of Hadamard matrices and designs.

Combinatorial Mathematics Society of Australasia - To facilitate, encourage, foster and cherish combinatorics throughout Australia, New Zealand and neighbouring countries.

Matroid Theory - Books, bibliography, software, links to home pages.

Matroids and Signed Graphs - Definitions, examples and representability problems.

Home Pages of Combinatorial People and Groups - Personal home pages of combinatorialists, graph theorists, and others with an interest in discrete mathematics.

Researchers in Combinatorics - Compiled at JCCA.

Diamond Theory - This site states a combinatorial theorem that provides a new approach to a number of topics in finite geometry, finite group theory, and combinatorics.

Some Problems in Matroid Theory - Compiled by Thomas Zaslavsky.

Combinatorics/Number Theory at Texas A&M - Graph theory, combinatorial number theory.

Krawtchouk Polynomials Home Page - An exposition of the properties and applications of these classical orthogonal polynomials introduced by M. Krawtchouk in 1929.

Discrete Mathematics Conferences, Workshops, Events - From DMV-Fachgruppe Diskrete Mathematik.

SOMA Update - Leonard Soicher reports on new SOMAs and new information on SOMAs, which are generalisations of mutually orthogonal latin squares.

Topics in Mathematics - Combinatorics - In the Mathematics Archive at UTK.

Open Problems for Undergraduates - A collection of open problems in Discrete Mathematics which are currently being researched by members of the DIMACS community.

Open Problems in Discrete Mathematics - From the SIAM DM activity group newsletter and other sources.

La Jolla Covering Repository - Upper and lower bounds on the minimum size of a covering design, i.e., for a set with v elements, the minimum number of subsets with k elements, some of which contains each subset with t elements, for various v, k, and t.

Design Resources - Links to web-based resources for design theory and related parts of discrete mathematics and statistics (coding theory, finite geometry, combinatorics, graph theory), including an annotated list of lecture notes.

The Boise Problem Book - By Marion Scheepers. Combinatorial games and set theory.

Extremal Combinatorics - With Applications in Computer Science, by Stasys Jukna. Preface, contents, errata.

Past Open Problems - From the SIAM Activity Group Newsletter in Discrete Mathematics. In PostScript. Compiled by Douglas B. West.

Encyclopedia of Combinatorial Structures - Searchable database of structures with specifications and counts.

Golomb Ruler Table - The lengths of the shortest known Golomb rulers for up to 150 marks. The values for 23 marks or less are known to be optimal.

Combinatorial Catalogues - Interesting combinatorial objects, such as graphs, designs, geometries; collected by Gordon Royle.