Businessman, Philanthropist. Paul Gardner Allen was an American business magnate, investor, and philanthropist. He co-founded Microsoft alongside Bill Gates in 1975. In August 2018, he was estimated to be the 46th-richest person in the world, with an estimated net worth of $20.2 billion. Allen was the founder and Chairman of Vulcan Inc., which manages his various business and philanthropic efforts. Allen had a multibillion-dollar investment portfolio including technology and media companies, scientific research, real estate holdings, private spaceflight ventures, and stakes in other companies. He owned two professional sports teams: The Seattle Seahawks of the National Football League and the Portland Trail Blazers of the National Basketball Association and was part-owner of the Seattle Sounders FC, which joined Major League Soccer in 2009. He was the founder of the Allen Institute for Brain Science, Institute for Artificial Intelligence, Institute for Cell Science, and Stratolaunch Systems. Throughout his lifetime, Allen gave more than $2 billion towards causes such as education, wildlife and environmental conservation, the arts, health and community services, and more. In the late 1960's, Allen met his future business partner Bill Gates while attending Lakeside School, a private day school located on the shores of Lake Washington. The two shared an interest in technology and by 1975, in Albuquerque, New Mexico, Allen and Gates, both college drop-outs began marketing a BASIC programming language interpreter. Allen came up with the original name of "Micro-Soft," according to a 1995 Fortune magazine article. In 1980, after promising to deliver IBM a Disk Operating System (DOS) they had not yet developed for the Intel 8088-based IBM PC, Allen spearheaded a deal for Microsoft to purchase a Quick and Dirty Operating System (QDOS) written by Tim Paterson, who, at the time, was employed at Seattle Computer Products for $50,000. As a result of this transaction, Microsoft was able to secure a contract to supply the DOS that would eventually run on IBM's PC line. This contract with IBM proved the watershed in Microsoft history that led to Allen's and Gates' wealth and success. Allen effectively left Microsoft in 1983 due to a serious illness, he was diagnosed with Hodgkin's lymphoma. Allen wrote in a 2011 book, Idea Man, that he told his Microsoft co-founder Bill Gates in June 1982 that he planned to leave the company they created in 1975 over differences in management and ownership stakes. Later that year, he received a diagnosis of Hodgkin’s lymphoma. Allen received one of the most extreme cancer treatments available, typically reserved for patients who have exhausted other options. It typically involves massive doses of radiation to kill off malignant cells, followed by a bone-marrow transplant. He recovered from that bout, and left Microsoft in February 1983, though remained on the board for nearly two decades. Allen officially resigned from his position on the Microsoft board of directors in November 2000 but was asked to consult as a senior strategy advisor to the company's executives. In the mid-1980's, Bill Gates reportedly asked Allen to give him some of his shares to compensate for the higher amount of work being performed by Gates. Allen thought this was warranted; however, when the time came for the adjustment to occur, Gates decided not to proceed. Instead, Gates tried to buy Allen out at a low price, however, Allen refused and left the company with his shares intact. This proved critical to Allen becoming a billionaire after Microsoft went public on March 13, 1986, at an offer price of $21.00 per share. By the end of the day, the stock price had risen to $35.50 per share. At the time of his death, Allen owned a reported 100 million shares of Microsoft stock. In 2009 Allen was diagnosed with non-Hodgkin's lymphoma and it went into remission. It was a similar form of cancer that led to his early retirement from Microsoft in February 1983. On October 1, 2018, Allen announced he had been diagnosed with cancer. This was the third time that the Microsoft co-founder had been diagnosed with cancer, this time a recurrence of non-Hodgkin’s lymphoma (NHL) and on October 15, 2018, the director of philanthropic communications of Allen's investment company, Vulcan, announced that Allen had passed away due to complications from his cancer, he was 65 years old. Allen never married and had no children.