R and S Erection
Produces wood folding doors and commercial sectional doors.
http://www.rs-erectionofsc.com/

Spazio
Producer of folding doors.
http://www.spazio.co.uk

Panelfold
folding doors, acoustical folding partitions, operable walls, operable partitions, demountable partitions, relocatable partitions, portable panels, moveable walls, accordion doors, accordion partitions, acoustical panels. In it's fifth decade, panelfold is recognized as the innovative leader in folding doors, acoustical accordion folding partitions and operable and relocatable walls.
http://www.panelfold.com/

FSD (UK)
Folding Sliding Doors, sliding folding door, sliding door, folding doors, patio doors, bifold, exterior door, patio door, french door, wooden and timber door manufacturer,
http://www.foldingslidingdoors.co.uk

Specialty Doors
Interior doors, glass doors, sliding glass doors, acoustical doors, traffic doors, frameless glass doors, frosted glass doors, exterior folding doors, and door hardware.
http://www.specialtydoors.com/

Sunflex USA, LLC
Manufacturing custom sliding and folding glass doors for indoor pools, patios and restaurants.
http://www.sunflexusa.com/

Besam
Manufacturer of Automatic Doors: Sliding, Swinging, Telescoping, Revolving, Service, access controls and sensors.
http://www.besam.com

Clegg Co.
AAA Material Handling Equipment, ALL PRODUCTS PRICED OUT, by Clegg Co. sells industrial supplies and equipment.
http://www.forkliftcosts.com/

Pella Doors and Windows
Premium Grade windows, patio doors, entry doors, storm doors and skylights. Available in the U.S. and Canada.
http://www.pella.com

Moderco
Manufacturer of dividing products such as folding walls, accordian doors, divider curtains and electrical gymnasium walls.
http://www.moderco.com