Microsoft co-founder Paul Allen dead at 65

Microsoft co-founder Paul Allen has died at the age of 65.

Paul Allen recently revealed his non-Hodgkin's lymphoma that he was treated for in 2009 had returned. "My team of doctors has begun treatment of the disease and I plan on fighting this aggressively," he wrote in a post on the website on Oct. 1.

Allen wrote that a lot has happened since he overcame the disease in 2009 saying, "My doctors are optimistic that I will see good results from the latest therapies, as am I."

Allen founded Microsoft alongside Bill Gates in 1975. He was the founder and chairman of Vulcan Inc. He owned two professional sports teams including the Seattle Seahawks and Portland Trail Blazers.

Allen's sister, Jody, said her brother "was a remarkable individual on every level," and while most knew him for his work in technology and philanthropy, "he was a much loved brother and uncle, and an exceptional friend."

Additional details on his death have not been released.