SAN JUAN, Puerto Rico — James Martin, a British philanthropist and technology guru who was once the highest-selling author on books about computing, has died near his private island in Bermuda. He was 79.

Authorities in the British territory said Thursday that an autopsy is pending for Martin, whose body was found by a kayaker in waters near his home on Agar's Island. Police have said they do not believe a crime is involved.

Martin was the largest single private donor in the nearly 900-year history of the University of Oxford, donating more than $150 million to help establish the Oxford Martin School, where researchers study global issues, challenges and opportunities facing humanity in the 21st century. Project topics range from climate change to quantum physics to the future of food.

Martin also was a Pulitzer Prize nominee for a 1977 technology book, "The Wired Society," which Oxford University said contained descriptions about the use of computers and the Internet that was still timely a quarter of a century later. The university also noted that Martin was ranked fourth in Computer World's 25th Anniversary Edition's most influential people in computer technology. He is also credited with helping automate software development.

"You rarely meet someone who's such an incredible philanthropist whose sole interest is doing good at the highest level," said Dr. Anthony Knap, director of the Geochemical and Environmental Research Group at Texas A&M University. "I think it's a tragic loss. He was an innovative man who could have continued doing good."

Knap, who previously worked in Bermuda, told The Associated Press in a phone interview that he had known Martin for about 18 years and considered him a very modest and gentle man.

"He was a bit of an enigma," Knap said. "For a long time he was in the background, which didn't really fit into his level of success."

Martin traveled around the world to give lectures and is an honorary life fellow of the British Royal Institution and a fellow of the World Academy of Art and Science.

He wrote more than 100 textbooks and published books including "The Meaning of the 21st Century," which was made into a film narrated by actor Michael Douglas. It analyzes technological, political, ethical, social and environmental issues of modern times.

Professor Ian Goldin, director of the Oxford Martin School, said in an email to the AP that Martin had a passion for changing to world for the better and described his intellect as extraordinary and wide-ranging.

"His aim was to harvest the opportunities of the 21st century and stop terrible risks materializing," Goldin wrote. "He was interested in everything and people of all ages, especially young people."

Goldin said Martin also was passionate about his garden, theater and music, as well as walking and traveling.

He leaves behind a wife, Lillian, a daughter, two grandchildren and four stepchildren.