UPDATE: Bill Gates penned extended thoughts about the passing of his friend and and fellow Microsoft Co-founder Paul Allen on his blog.

“When I think about Paul, I remember a passionate man who held his family and friends dear,” Gates wrote. “I also remember a brilliant technologist and philanthropist who wanted to accomplish great things, and did.”

“Paul deserved more time in life. He would have made the most of it. I will miss him tremendously.”

Original story below

Bill Gates and Paul Allen founded Microsoft together in 1975, cementing the pair as legends in the world of technology.

Allen passed away Monday, and not long after Gates reflected on his time with his partner and friend in a statement:

I am heartbroken by the passing of one of my oldest and dearest friends, Paul Allen. 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. Personal computing would not have existed without him. But Paul wasn’t content with starting one company. 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. 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. Paul loved life and those around him, and we all cherished him in return. He deserved much more time, but his contributions to the world of technology and philanthropy will live on for generations to come. I will miss him tremendously.

Allen and Gates, both computer enthusiasts, met when they were students at Lakeside School in Seattle at ages 14 and 12. Allen, whose father was associate director of libraries at the University of Washington, spent a good amount of time with Gates and other friends in UW’s Computer Science Laboratory. So much so, that he received a letter in 1971 when he was a high school senior, informing him that he would no longer have access to the UW’s graduate computer lab.

It was at UW where Allen and Gates launched their first venture, a startup that developed a computer system to count traffic called Traf-O-Data.

Allen reflected on the venture last year during an event to christen the University of Washington’s Paul G. Allen School of Computer Science & Engineering.

Objectively speaking, Traf-O-Data was a failure as a company. Right as our business started to pick up, states began to provide their own traffic-counting services to local governments for free. As quickly as it started, our business model evaporated. But while Traf-O-Data was technically a business failure, the understanding of microprocessors we absorbed was crucial to our future success. And the emulator I wrote to program it gave us a huge head start over anyone else writing code at the time. If it hadn’t been for our Traf-O-Data venture, and if it hadn’t been for all that time spent on UW computers, you could argue that Microsoft might not have happened.

Together, they founded Microsoft in 1975. The original idea behind the company, whose name Allen reportedly derived from a portmanteau of microcomputer and software, was to build an implementation of a programming language for a new microcomputer.

Like any long-term friendship, Allen and Gates had their rocky moments. Allen’s 2011 memoir “Idea Man,” reportedly created a rift among the two titans, as the book brought to light previously unknown details about their relationships included tense negotiations over Microsoft equity and Allen’s departure from the company when he was originally diagnosed with non-Hodgkin’s lymphoma.