N-(phosphonomethyl)glycine, or C3H8NO5P. White, odourless powder, soluble in water.
Gylphosate is an organophosphate broad-spectrum herbicide, used primarily on grasses and deep-rooted perennial weeds, which are otherwise difficult to root out completely. It is absorbed by a plant's leaves, and spreads throughout the entire organism from there. It interferes with the plant's metabolic processes, killing it after a few days.
It is the active ingredient in the commercial weedkiller Roundup, manufactured by Monsanto. Monsanto also produce a variety of seed products (such as corn and soy) containing the "Roundup Ready" gene. This gene conveys resistance to glyphosate. Farmers can spray Roundup directly over resistant crops, so reducing the cost of weed control.
Unlike some organophosphates, glyphosate is not (very) toxic to humans or animals. The Monsanto web site (www.monsanto.com) is very useful in providing information such as a list of toxicology studies which have been performed on their products for the purposes of regulatory compliance. It notes, for example, that glyphosate is classified by the EPA as a "Category E" herbicide, which means that there is positive evidence of non-carcinogenicity in humans.
Most of the controversy surrounding the Roundup product family centres on the genetically modified Roundup Ready crops. Glyphosate itself is widely considered to be unobjectionable (as these things go)