Leaders in Silicon Valley, entertainment, and professional sports are remembering Microsoft cofounder Paul Allen, who died after a battle with cancer at 65

Paul Allen, the cofounder of Microsoft and billionaire philanthropist, died Monday afternoon after battling non-Hodgkin's lymphoma.

The 65-year-old Seattle native is best-known for having launched Microsoft with Bill Gates, but he also operated the venture-capital firm Vulcan Ventures, and staked his claim on sports franchises as the owner of the Seattle Seahawks and Portland Trail Blazers.

Allen previously overcame a bout of Hodgkin's lymphoma in the 1980s, but he was later diagnosed with cancer in 2009, which returned after a period of remission.

As a titan in the tech industry and the world of sports, Allen influenced his colleagues to inspire millions of others through their work.

Here's how Allen's friends and associates are responding to his death.