Roof Genius
Roof calculator, calculates a detail list of roof materials, and a complete estimate. Two ways to determine roof pitch. Offers tips and how to's on roofing. [Windows 95/98/2000/Me/XP/NT]
http://roofgenius.com/

The Roof Group
California based commercial roof management and consulting firm specializing in inspections, maintenance, repairs, construction management.
http://www.theroofgroup.com/

Rib Roof Inc.
Design, manufacture and installation of metal roofing and self-storage building systems. Includes a construction specification handbook, product specification sheets and a rib roof technical manual.
http://www.ribroof.com/

Decra Roof Systems:
Roof coverings using lightweight roof tiles for all roofs down to a ten degree pitch. UK.
http://www.decra.co.uk/

Roof Products, Inc.
Manufacture prefabricated roof curbs and other roof accessories. Products include expansion joints, equipment supports, adapters, and ice deflectors.
http://www.rpicurbs.com/

Roof Coatings Manufacturers Association
Roof Coatings Manufacturers Association (RCMA) represents manufacturers of cold-applied roof coatings and cements. RCMA’s site offers product information and the latest roof coating news.
http://www.roofcoatings.org/

Fibreglass Roof Decking
Roof Decking From Dura Composites Ltd
http://www.roofdecking.co.uk

ARCON Associates, Inc.
ARCON Associates, Inc., began in 1979 planning, programming and designing educational facilities. Today we provide architectural and construction related services to school districts, park districts, municipalities and commercial clients.
http://www.arconassoc.com

American Hydrotech, Inc.
Hydrotech’s Green Roof, the Garden Roof Assembly is the latest innovation in roofing/waterproofing using MM6125 and 40+ years of successful installations around the world.
http://www.hydrotechusa.com/

Roof Menders
Tin Roofs: protecting our rich heritage against leaks and rust
http://www.roofmenders.com/