Allen succumbed to non-Hodgkin's lymphoma. He died Monday afternoon in his hometown of Seattle.
Allen, whose wealth was estimated north of $20 billion, announced 2 weeks ago his cancer had returned after 9 years in remission.
Some personal news: Recently, I learned the non-Hodgkin’s lymphoma I battled in 2009 has returned. I’ve begun treatment & my doctors are optimistic that I will see a good result. Appreciate the support I’ve received & count on it as I fight this challenge. https://t.co/ZolxS8lni5
Allen and Gates, both college dropouts, hatched the idea for Microsoft in Albuquerque. They designed software for the yet-to-explode personal computer revolution.
The 2 men met when they were teenage students at Lakeside School outside Seattle. They became fast friends and bonded over their love of computers. The two would go "dumpster diving" for computer program code. Allen, who dropped out of Washington State, convinced Gates to bail from Harvard.
Allen is the one who came up with the name -- Micro-Soft.
The company moved to Bellevue, Washington in 1979. He was diagnosed with non-Hodgkin's lymphoma in 1983 and resigned shortly thereafter, but still was an active member of the board until 2000.
Allen bought the Seattle Seahawks back in 1996, 8 years after buying the Portland Trail Blazers. He also bought the Seattle Sounders, part of Major League Soccer, with business partners including Drew Carey.
Allen was a huge music fan, especially of Jimi Hendrix, and founded The Experience Music Project Museum in Seattle.
Paul donated more than $2 billion to various charities.
Allen was never married and had no children.
Paul's family says, "For all the demands on his schedule, there was always time for family and friends. At this time of loss and grief for us -- and so many others -- we are profoundly grateful for the care and concern he demonstrated everyday."