Gypsum Association (USA)
Represents manufacturers of gypsum board in the U.S. and Canada and provides technical information and assistance to the construction industry and code enforcement community regarding gypsum board.
http://www.gypsum.org/

GP Gypsum Corporation
Gypsum at Georgia Pacific Building Products. High quality gypsum wallboards and gypsum drywall from one of North America’s leading gypsum board manufacturers.
http://www.gp.com/build/ProductGroup.aspx?pid=1064

DKT Co.,Ltd.
GreenCal, Agricultural Gypsum high purity gypsum. GreenCal is suitable for agricultural to improve soils structure with natural substances.
http://www.dktgypsum.com/

Gypsum Technologies Inc.
Canada. Offers engineering design, equipment supply, project and construction management, commissioning, and technical services for the gypsum wallboard manufacturing industry.
http://www.gypsumtechnologies.com

National Gypsum Company
A fully-integrated manufacturer and supplier of products and services used worldwide in building and construction, with primary emphasis on gold bond brand gypsum wallboard and joint treatment compounds.
http://www.nationalgypsum.com

Processed Gypsum Products Australia
Offers Gypsum which is 100% natural and will increases crop quality, yields and improve soil structure. Hi-Ag, Turf-Gyp, Micro-Gyp products benefit a wide range of agricultural enterprises.
http://www.pgp.com.au

North Pacific Group
North Pacific Ag Products distributes pelletized, solution grade, food and pharmaceutical grade and general agriculture grade gypsum products.
http://www.gypsumsales.com/

Permafloors
High strength and flat gypsum subfloors for new construction or rehabilitation.
http://www.permafloors.com/

Gib
Building design resource for gypsum plasterboard, drywall systems and compounds.
http://www.gib.co.nz

Umehiko
Natural stone tiles, roofing, and gypsum fibrous plaster manufacturer.
http://www.ahe-online.com