IG Farben

IG Farben (short for Interessen-Gemeinschaft Farbenindustrie
AG), was a group of German chemical companies formed in 1925. "Farben" is German for "paints", "dyes", or "colors". 
Initially most of these companies produced dyes, but soon began to do more advanced chemistry. The founding of IG Farben was a reaction to Germany's defeat in World War I. IG Farben held a near total monopoly on chemical production. 
IG was the company which produced chemical weapons which were available to the Wehrmacht in WWII. These included nerve gases which were never used against the allied armies for the reason that the Allies were though to have the same capability. However, Zyklon B was used in the Holocaust to murder Jewish prisoners. The SS was an authorized applier of the chemical.