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

Bill Gates, Microsoft founder and philanthropist

"I am heartbroken by the passing of one of my oldest and dearest friends," Gates said in a statement to The Wall Street Journal on Monday. "Paul was a true partner and dear friend."

Gates and and Allen were high-school friends; they founded Microsoft in 1975.

"Personal computing would not have existed without him," Gates said.

Tim Cook, Apple CEO

"Our industry has lost a pioneer and our world has lost a force for good," Cook said in a tweet on Monday. "We send our deepest condolences to Paul’s friends, the Allen family and everyone at Microsoft.

Sundar Pichai, Google CEO

"We lost a great technology pioneer today - thank you Paul Allen for your immense contributions to the world through your work and your philanthropy," Pichai said Monday. "Thoughts are with his family and the entire Microsoft community."

Jeff Bezos, Amazon CEO

"Very sad to hear of Paul Allen's passing," Bezos said. "His passion for invention and pushing forward inspired so many. He was relentless to the end."

Satya Nadella, Microsoft CEO

"Paul Allen's contributions to our company, our industry and to our community are indispensable," Nadella said in a statement. "As co-founder of Microsoft, in his own quiet and persistent way, he created magical products, experiences and institutions, and in doing so, he changed the world."

"I have learned so much from him — his inquisitiveness, curiosity and push for high standards is something that will continue to inspire me and all of us at Microsoft," he added. "Our hearts are with Paul's family and loved ones. Rest in peace."

Marc Benioff, Salesforce CEO

"Saddened by the passing of Paul Allen a great leader in tech and a man of all seasons who fully enjoyed his life and wealth yet also gave back to the world at scale," Benioff said. "I was especially impressed with how he took care of the Oceans. May the one who brings peace bring peace to all."

Steve Wozniak, Apple cofounder and entrepreneur

"I was in an on-stage interview when my moderator presented the news," Wozniak told Business Insider senior reporter Greg Sandoval. "I could barely continue. I felt great grief for the world."

"Paul has done so much for humanity and his values are tops," he added. "Paul cared about the effect of technology on society. I'm sad and shed a few tears after my event here in Melbourne. I hope that there are more like Paul in the future."

Pete Carroll, Seattle Seahawks head coach

Allen has been the owner of the Seattle Seahawks since 1996.

"Deeply saddened by the passing of Paul Allen," Carroll said. "I'll miss him greatly. His gracious leadership and tremendous inspiration will never be forgotten."

"The world is a better place because of Paul's passion, commitment, and selflessness," he added. "His legacy will live on forever."

Adam Silver, NBA commissioner

Allen has owned the Portland Trail Blazers since 1988.

"Paul Allen was the ultimate trail blazer – in business, philanthropy and in sports," NBA commissioner Adam Silver said in a statement. "As one of the longest-tenured owners in the NBA, Paul brought a sense of discovery and vision to every league matter large and small."

Steve Ballmer, former Microsoft CEO

"Paul was a truly wonderful, bright and inspiring person — and a great friend," Ballmer said on Monday. "I will miss him."

"I also want to add that Paul’s insights were critical to the creation and success of Microsoft," he added. "He was a great professional mentor and teacher for me."

Ballmer, who also owns the Los Angeles Clippers, shared how Allen encouraged him to get involved with the NBA.

"And last Paul told me for years that I should own an [NBA] team," Ballmer tweeted. "He used to yell at me '[Steve], you got to do it, it will fire you up.' That too changed my life for the better."