New Delhi, Oct 16: Earlier this month, Microsoft co-founder and philanthropist Paul Allen announced that cancer he was last treated nine years ago had returned and he would aggressively fight it again.Little did the world realise that this time, non-Hodgkin's lymphoma (an uncommon cancer of the lymphatic system) would not even give a month's time to Allen.In his own words: "As long as we work together -- with both urgency and determination -- there are no limits to what we can achieve". Allen died on Monday in Seattle, aged 65.Allen never retired. After he left the company in 1983 he co-founded with Bill Gates in 1975, he became a philanthropist and went on to help millions across the world live with dignity and disease-free.Despite always staying in the shadow of Gates -- his partner and friend since they were teenagers -- Allen was a passionate lover of computers and a key figure in the creation of Microsoft.Born in Seattle, Washington State in 1953, Allen's wealth rose to over $20 billion this year, making him the world's 44th-richest person.In 1968, while at Lakeside School, he met Gates -- a friendship that later produced one of the world's most innovative companies.Allen was diagnosed with Hodgkin's lymphoma (another form of cancer in the lymphatic system) in 1982. Nearly eight months later, doctors said he had beaten the disease. But the diagnosis probably changed his life.In 1983, he officially resigned from Microsoft and three years later, Allen founded Vulcan Inc. in Seattle as an investment and project management firm with his sister, Jody Allen.In 1988, Allen established The Paul G. Allen Family Foundation and in the same year, purchased the Portland Trail Blazers -- a famous baseball team commonly known as the Blazers.At age 37, he was already a billionaire and in 1995, made his single biggest investment to date by purchasing a 18.5 per cent stake in the Dreamworks, animation studio that is a subsidiary of Universal Pictures.Two years later, Allen purchased the Seattle Seahawks, preventing the National Football League (NFL) team from relocating to California.In 2002, he donated $14 million to the University of Washington to construct the Paul G. Allen Center for Computer Science and Engineering and in 2003, launched the Allen Institute for Brain Science (AIBS) with $100 million in seed money.In his lifetime, he donated nearly $1 billion towards various causes.The Vulcan Inc. is the engine behind Allen's network of organisations and initiatives. With headquarters in Seattle, Vulcan oversees and manages a broad compilation of projects, investments and companies all over the world. Allen has been a leader in the fight against Ebola, committing $100 million to the effort and developing a programme in 2014 that brought strategic and targeted solutions to the global response to the outbreak.Allen's love for Bollywood was also evident when in 2015, he threw a bash on board his yacht called the Octopus. According to a Quartz report, actor Mallika Sherawat performed in the presence of Hollywood stars like Natalie Portman, Antonio Banderas and Leonardo DiCaprio as large elephant and Buddha statues were seen.When it comes to Microsoft, Allen was always there."Paul Allen's contributions to our company, our industry and to our community are indispensable. 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," said CEO Satya Nadella on his demise.His philanthropic work includes creating organisations devoted to research such as the Allen Institute for Brain Science, along with the Institute for Artificial Intelligence and the Institute for Cell Science, both of which also bear his name."I have the honour to work at Microsoft because of the early work of Paul Allen. Paul has had immeasurable impact on the tech industry and the Seattle community. He will be deeply missed," noted company President Brad Smith.When Allen got the news from doctors earlier this month that his cancer has returned, he said in a statement: "A lot has happened in medicine since I overcame this disease in 2009. My doctors are optimistic that I will see good results from the latest therapies, as am I".However, a lot is yet to happen in the world of medicine -- and technology, which Allen mastered early in his life -- will probably show the way.