Science News for Kids: MatheMUSEments
Description of Durer's square and an alphamagic square.
http://www.sciencenewsforkids.org/pages/puzzlezone/muse/muse1103.asp

MathWorld: Panmagic Square
Demonstration of the properties of a pan-magic square.
http://mathworld.wolfram.com/PanmagicSquare.html

Square Domes International
Square and rectangular dome designers for residential and any other use that can be thought of. Includes profile, ray traced examples and contacts.
http://squaredomes.tripod.com/

Square Sail Ship Yard Ltd.
Square Sail Shipyard Ltd - The world's last working fleet of sailing ships. Available for films, corporate events and training voyages
http://www.square-sail.com/film_tv_facilities/index.html

Brand Flowers, Inc.
We grow high quality california grown, strong, long lasting flowers that are full of color, including lilies, gerberas, tulips, dahlias, sunflowers, snapdragons, flowering kale as well as sell consumer bunches, growers bunches, and bouquets.
http://www.brandflowers.com/

A Very, Very Magic Square
A 25x25 magic square with 25 sub-squares and other properties. Maple program and PostScript files available for download.
http://www.math.lsa.umich.edu/~hderksen/magic.html

Formulating Rations With the Pearson's Square (PDF)
The Pearson square ration formulation procedure is designed for simple rations. In order for the square to work, follow specific directions for its use. Nutrient contents of ingredients and nutrient requirements must be expressed on the same basis (i.e., dry-matter or as-fed).
http://www.ext.colostate.edu/pubs/livestk/01618.html

Simple Magic Square Checker
Enter numbers and display the magic square in gif or jpg formats.
http://www.geocities.com/CapeCanaveral/Lab/3469/squaremaker.html

Sing Square Log Homes, Inc.
Sing Log Homes produces high quality milled logs, timbers and lumber for use in log homes,log home cabins,log siding,log home kits,log cabins,modular log homes,log cabin kits.
http://www.singloghomes.com

The Anti-Magic Square Project
Starting from the definition of an Anti-Magic Square (AMS), the article presents the structure and construction methods of the AMS. Programs written in the c-language are available for download.
http://io.uwinnipeg.ca/~vlinek/jcormie/