Iconic tech-company founders often come in pairs: Bill Hewlett and David Packard. Steve Jobs and Steve Wozniak. Sergey Brin and Larry Page. The world lost half of one such duo Monday when Paul Allen, who cofounded Microsoft with his childhood friend Bill Gates, died from non-Hodgkin's lymphoma. He was 65. For the last three decades of his life, Allen was best known as a philanthropist and prolific entrepreneur.

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