Paul G. Allen, the co-founder of Microsoft who helped usher in the personal computing revolution and then channeled his enormous fortune into transforming Seattle into a cultural destination, died on Monday in Seattle. He was 65.
The cause was complications of non-Hodgkin’s lymphoma, his family said in a statement.
The disease recurred recently after having been in remission for years. He left Microsoft in the early 1980s, after the cancer first appeared, and, using his enormous wealth, went on to make a powerful impact on Seattle life through his philanthropy and his ownership of the N.F.L. team there, ensuring that it would remain in the city.
Mr. Allen was a force at Microsoft during its first seven years, along with his co-founder, Bill Gates, as the personal computer was moving from a hobbyist curiosity to a mainstream technology, used by both businesses and consumers.
When the company was founded, in 1975, the machines were known as microcomputers, to distinguish the desktop computers with the hulking machines of the day.
Mr. Allen came up with the name Micro-Soft, an apt one for a company that made software for small computers. The term personal computer would become commonplace later.
The company’s first product was a much-compressed version of the Basic programming language, designed to suit those underpowered machines.
Yet the company’s big move came when it promised the computer giant IBM that it would deliver the operating system software for IBM’s entry into the personal computer business. Mr. Gates and Mr.
Allen committed to supplying that software in 1980. At the time, it was a promise without a product. But Allen was instrumental in putting together a deal to buy an early operating system from a programmer in Seattle.
Mr. Allen and Mr. Gates tweaked and massaged the code, and it became the operating system that guided the IBM personal computer, introduced in 1981.
That product, called Microsoft Disk Operating System, or MS-DOS, was a watershed for the company. Later would come Microsoft’s immensely popular Windows operating system.
It was designed to be used with a computer mouse and onscreen icons — point-and-click computing rather than typed commands.
The company would also produce the Office productivity programs for word processing, spreadsheets and presentations.
“In his own quiet and persistent way, he created magical products, experiences and institutions, and in doing so, he changed the world,” Satya Nadella, Microsoft’s current chief executive, said of Mr. Allen in a statement.>