Microsoft Corp. (MSFT) co-founder Paul Allen, one of the main figures responsible for bringing personal computers to the masses, has passed away.

The billionaire philanthropist and investor’s company Vulcan Inc. announced that Allen died in Seattle at 65-years-old from complications of non-Hodgkin's lymphoma on Monday afternoon.

Bill Gates, Alllen’s childhood friend and former business partner, led the tributes. “From our early days together at Lakeside School, through our partnership in the creation of Microsoft, to some of our joint philanthropic projects over the years, Paul was a true partner and dear friend. Personal computing would not have existed without him,” he said in a statement.

Pioneer

Microsoft was founded in 1975 by Allen and Gates. During the company’s first seven years, Allen played a critical role in transforming personal computers into a mainstream technology.

According to The New York Times, it was Allen who persuaded Gates to drop out of Harvard and move to Albuquerque to set up Microsoft. Shortly after, the pair focused on supplying MITS, a start-up that had built a machine credited as the first personal computer, with software. Together they developed Microsoft Basic, an adaption of a popular programming language used on larger computers, for the first microcomputers.

Allen, who first came up with the name Micro-Soft, a reference to making software for small computers, was also influential in securing arguably the tech giant’s biggest breakthrough. In 1980, he helped to secure a nonexclusive license for the DOS operating system and then, the following year, the rights to provide the software — renamed MS-DOS — for International Business Machines Corp. (IBM) personal computers. That landmark deal paved the way for Microsoft to emerge as a leader of the PC boom.

“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 CEO, said in a statement

After laying down the foundations for Microsoft to thrive, Allen quit his role as chief technologist at the company in 1983. His resignation was attributed to him being diagnosed with Hodgkin disease and tensions with other key executives, Gates and Steven Ballmer. He did, however, remain on Microsoft’s board until 2000.

In recent years, Allen dedicated his time to supporting research in artificial intelligence and new frontier technologies and investing in his native Seattle. He also owned two professional sports teams, the NFL Seattle Seahawks and NBA Portland Trailblazers, and was ranked 44th on Forbes' 2018 list of billionaires with an estimated net worth of more than $20 billion.

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