Flax is one of the oldest domesticated species. It is unusual in that it was domesticated for two very different phenotypes, namely, for an unbranched stem for long fibers for linen (flax) production and a small shorter bushy phenotype for high seed yield (linseed). These two contrasting commercial phenotypes have more recently been augmented by the increasing use of flax as an important source of fiber, of omega-3 fatty acids, of plant estrogens, and of lignans in the diets of both humans and animals. Canada was the first country to support a health claim for flax that provides the highest plant-based source of unsaturated fatty acids. New value-added markets for flax in the human health and animal nutrition realm, as well as the fiber and oil being used for an array of industrial products including linoleum flooring, car panels, industrial oils, and solvents, and a myriad of other composite materials are important in the revival of this important oilseed and fiber crop. In addition, it has commercial potential that is changing with new opportunities. The use of fibers in composite materials may be enhanced by the development of dual-purpose varieties, that is, those that have sufficient seed yield allied to high-quality fibers. Such a crop would have an environmental advantage as well as the straw, which would be useful without the need for disposal resulting in additional carbon sequestration.