The Paul Allen, who co-founded Microsoft along  with his childhood friend Bill Gates in the 1970s and next went on to become an investor, philanthropist and sports team owner, passed away on Monday after his battle with cancer at age 65.

Allen died just two weeks after publicly revealing that non-Hodgkin’s lymphoma he fought into remission nine years ago had returned.

“My brother was a remarkable individual on every level. While most knew Paul Allen as a technologist and philanthropist, for us he was a much loved brother and uncle, and an exceptional friend,” Allen’s sister Jody said in a statement announcing his death.

Soon after the news of his death broke out, several from the tech community, actors, and the NFL world came out to pay their tributes.

Oscar winner and environmentalist Leonardo DiCaprio wrote: “Sad to hear of the passing of Paul Allen, who was a strong advocate for environmental protection. He and the team at Vulcan played a pivotal role in developing the Shark Conservation Fund alongside LDF. His legacy lives on via his incredible work as a philanthropist and investor.”

“I have learned so much from him – his inquisitiveness, curiosity and push for high standards are something that will continue to inspire me and all of us at Microsoft,” Microsoft CEO Satya Nadella wrote in a statement