Graph Theory resources on the Web
There is a lot of graph theory material on the Web. 
The sample below is somewhat arbitrary:
the listed sites are not necessarily the best
nor the most representative.
Instructional material
Specialized topics
- 
A Journey through Intersection Graph County,
by Erich Prisner
 - 
Graph Coloring Page,
by Joseph Culberson 
 - 
Graph Coloring Problems,
by 
Tommy Jensen
and
Bjarne Toft
 - 
The Four Color Theorem,
by Robin Thomas
 - 
The four color theorem,
site of St. Andrews University (Scotland)
 -  
Four-Color Theorem,
site of Wolfram Research MathWorld
 - 
The Strong Perfect Graph Theorem,
page by Vašek Chvátal 
 - 
Perfect Problems,
page by Vašek Chvátal 
 - 
nauty
(a program for computing automorphism groups of graphs and digraphs),
by Brendan McKay
 - 
 Graphs,
 by Brendan McKay
 - 
Sandbox,
by Gary Fredericks
 
Graph Theory people
Links, dictionaries and encyclopædias
- 
Proof Wiki:
the online compendium of mathematical proofs
 - 
Graph Theory
page in the Wikipedia
 - 
Beautiful Conjectures in Graph Theory,
slides by Adrian Bondy
 - 
A. Schrijver, 
Survey of Problems, Questions, and Conjectures,
from the book
Combinatorial Optimization: Polyhedra and Efficiency 
 - 
Open Problem Garden,
hosted by Simon Fraser University
 - 
List of Combinatorial Problems,
by B. Mohar
 
 - 
Graph Theory and Combinatorics Open Problems,
by Douglas West
 - 
ISGCI:
Information System on Graph Class Inclusions:
what's known about particular graph classes
 - 
Graph Theory,
by Eric Weisstein,
in the Wolfram Research MathWorld
 - 
The MacTutor History of Mathematics Archive,
at the St. Andrews University (Scotland)
  
 - 
Peter Cameron's Blog
(Combinatorics, etc.)
 
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