Non-Euclidean

Book List on Non-Euclidean Geometry
From theTreasureTroves collection.
http://www.treasure-troves.com/books/Non-EuclideanGeometry.html

Euclidean and Non-Euclidean Geometry with The Geometer's Sketchpad
Conference talk by Scott Steketee with downloadable sketches.
http://www.dynamicgeometry.com/talks/Euc_Wien98/

Minkowskian geometry and quaternion algebras
An exploration of the geometry of quaternion algebra, including a commutative variant which exhibits the properties of Minkowskian geometry.
http://www.geocities.com/timsheltonjones/

NonEuclid - Hyperbolic Geometry Article & Applet
Software simulation offering straightedge and compass constructions in hyperbolic geometry.
http://cs.unm.edu/~joel/NonEuclid/NonEuclid.html

Non-Euclidean Geometry
A historical account with links to biographies of some of the people involved.
http://www-groups.dcs.st-andrews.ac.uk/~history/HistTopics/Non-Euclidean_geometry.html

Non-Euclidean Geometry - Mathematics and the Liberal Arts
A resource for student research projects and for teachers interested in using the history of mathematics in their courses.
http://math.truman.edu/~thammond/history/NonEuclideanGeometry.html

Non-Euclidean Geometry with LOGO
Review of a new version of LOGO developed at Cardiff.
http://www.bham.ac.uk/ctimath/reviews/logo.html

The Ontology and Cosmology of Non-Euclidean Geometry
A philosophical essay.
http://www.friesian.com/curved-1.htm

References for Non-Euclidean Geometry
A bibliographic reference list of books and articles on non-Euclidean geometries, part of the MacTutor History of Mathematics archive.
http://www-history.mcs.st-andrews.ac.uk/history/HistTopics/References/Non-Euclidean_geometry.html

Seminar on the History of Hyperbolic Geometry
Seminar notes by Greg Schreiber.
http://www.math.columbia.edu/~pinkham/teaching/seminars/NonEuclidean.html

Spherical Trigonometry, Arc Distance Formula
Finding the shortest distance between two points on the earth given latitude and longitude. Download ARC_CALC_3, Microsoft Excel version, A Spherical Triangle Calculator by James Q. Jacobs.
http://www.jqjacobs.net/astro/arc_form.html