In rec.boats.paddle Brian Nystrom wrote:

In case anyone actually cares, Spectra is the name of product Allied
Signal manufactures in the US under licence from Hoescht-Celanese in
Germany, the manufacturer of Dyneema. They are identical fibers, though
they can be made into a variety of products that may differ widely.

According to the Dyneema website, they are a Dutch company.

http://www.dsm.com/en_US/html/hpf/home_dyneema.htm

Spectra and Dyneema are both made of polyethylene, but is that evidence
to indicate they are really "the same thing"?

Specs indicate Dyneema-core ropes have slightly higher tensile strength
than Spectra and some marketing blurbs indicate they have a softer feel.