Microsoft Corp. co-founder Paul Allen passed away on Monday from complications of non-Hodgkin’s lymphoma.

Allen revealed two weeks ago that the disease had returned after he spent years battling and overcoming it. He said in a statement at the time that he believed he could beat it again.

“A lot has happened in medicine since I overcame this disease in 2009,” Allen said. “My doctors are optimistic that I will see good results from the latest therapies, as am I.”

When he was first diagnosed with NHL in 1982, Allen received an extreme form of treatment involving large amounts of radiation and a bone marrow transplant. He recovered and left Microsoft in 1983, although he remained on the board for many years to come. In 2009, he was diagnosed with NHL again.

“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,” Bill Gates, his Microsoft co-founder and once high school friend, said in a statement. “Personal computing would not have existed without him.”

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

— Tim Cook (@tim_cook) October 15, 2018

Outside of computing, Allen spent much of his time – and donated a lot of his money – to philanthropy and scientific research. It’s thought that he donated more than $2 billion toward technology, science, the arts, education and wildlife preservation through his Paul G. Allen Family Foundation.

He founded the Allen Institute for Brain Science, the Institute for Artificial Intelligence and the Institute for Cell Science. He also invested heavily in aerospace ventures, had a large real estate firm and a television and film production company, and he owned sports teams as well.

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

— Sundar Pichai (@sundarpichai) October 15, 2018

“He channeled his intellect and compassion into a second act focused on improving people’s lives and strengthening communities in Seattle and around the world,” Gates said in his statement. “He was fond of saying, ‘If it has the potential to do good, then we should do it.’ That’s the kind of person he was.”

Microsoft Chief Executive Satya Nadella called Allen’s contributions to technology “indispensable.” He added that Allen “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 as Microsoft.”

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.

— Jeff Bezos (@JeffBezos) October 15, 2018

A man of innumerable talents, Allen also had some more laid-back interests such as music, ocean travel and deep-sea exploration. He had a great admiration for musician Jimi Hendrix. Allen went on to create his own music and was an excellent guitarist according to reviewers.

Photo: YouTube