Ross Perot, the billionaire who made his fortune in the computer services industry, has died after a five-month battle with leukemia. He was 89. Perot founded Electronic Data Systems Corp. and sold it to G.M. for $1.5 billion in 1962. He ran for president twice as an Independent candidate in 1992 and 1996. In 2009, Dell purchased Perot Systems from him, leaving him with $800 million. According to Forbes’ most recent estimate, Perot was worth $4.1 billion. His son, Ross Perot Jr., current CEO of the Perot group, said in a statement that “at the end of the day, he was a wonderful humanitarian. Every day he came to work trying to figure out how he could help somebody.” Perot attempted to rescue hostages from Iran in 1979, a mission that became the basis of Ken Follet’s novel, On Wings of Eagles. He is survived by his wife Margot and his five children.