Paul Allen, the Microsoft co-founder who went on to become a major tech investor, philanthropist and civic leader, died Monday after a recurrence of cancer.

The big picture: Though Allen was personally low key, he made a major mark on the world, especially in his hometown of Seattle, where he helped cement the city's role.

He established a number of key institutions including the MoPop museum of pop culture and the Living Computers Museum, a gem of a place where you can try out many of the early devices that helped create the tech industry.

He also ran tech investor Vulcan, established the Allen Institute for Brain Science, owned the Seattle Seahawks and Portland Trailblazers, and did way more than Axios' format could allow me to list. Oh yeah, and he was one heck of a guitarist.

What they're saying:

• His Microsoft co-founder Bill Gates: "I am heartbroken by the passing of one of my oldest and dearest friends. Paul was a true partner and dear friend. Personal computing would not have existed without him.” (per Bloomberg)
• The Information's Nick Wingfield: "Paul Allen led the kind of life I think a lot of people would if they acquired unimaginable wealth. A combo of good deeds, bad investments, good investments, ridiculous toys and having somewhat obscene amounts of fun."
• Amazon's Jeff Bezos: "Very sad to hear of Paul Allen’s passing. His passion for invention and pushing forward inspired so many. He was relentless to the end. My heart goes out to Paul’s family and friends."
• Singer David Crosby: "damn...lost a friend we needed ...Paul Allen ...smart , decent man , ..good guitar player...funder of science ...saver of elephants ... A fine man."

Go deeper: Listen to this rare public interview from Seattle's GeekWire, recorded in 2011.