Abdul Qadeer Khan (; April 1, 1936 – October 10, 2021) was a Pakistani scientist and metallurgical engineer. He was a controversial figure. He is thought by many people to be one of the pioneers of Pakistan's nuclear program. Others disagree and claim he is only an opportunist who abused his position to obtain personal benefits and make a lot of money. His middle name is occasionally spelt Quadeer, Qadir or Gadeer. His given names are usually abbreviated to A.Q.. 