# Useful Links

Links

## Computational Geometry

CGAL (Computational Geometry Algorithms Library) at Utrecht

## Graph Theory

Combinatorial data by Brendan McKay:

Graphs: including simple, Eulerian, Chordal, Perfect, Strongly regular, Planar, etc. click here

Digraphs: including simple, oriented, tournament, locally transitive tournament, DAG. Click here

You can:

check the relation between graph classes and get a witness for the result

draw clear inclusion diagrams

colour these diagrams according to the complexity of selected problems

find the P/NP boundary for a problem

save your diagrams as Postscript, GraphML or SVG files

find references on classes, inclusions and algorithms

Visualisation tool for exploring tree decompositions

## Group Theory

Finite groups of order ≤500, group names, extensions, presentations, properties and character tables, click here

## Miscellaneous Links

GAP (Groups, Algorithms, Programming) at St. Andrews

Geometry Center (Downloadable Software page)

LEDA (Library of Efficient Datatypes and Algorithms) at Max Planck

AGD (Automatic Graph Drawing) at Max Planck

ALCOM-IT (Algorithms and Complexity in Information Technology)

Algorithms Project at INRIA

P.Brinkman's Train Track software

Vacancy