Bill Gates had an estimated net worth of US$90.6 billion at the time. , Gates had a net worth of $95.4 billion, making him the second-richest person in the world, behind Bezos. Later in his career and since leaving Microsoft, Gates pursued a number of philanthropic endeavors. He donated large amounts of money to various charitable organizations and scientific research programs through the Bill & Melinda Gates Foundation. In 2009, Gates and Warren Buffett founded The Giving Pledge, whereby they and other billionaires pledge to give at least half of their wealth to philanthropy. The foundation works to save lives and improve
Bill Gates retail version of Microsoft Windows on November 20, 1985. In August of the following year, the company struck a deal with IBM to develop a separate operating system called OS/2. Although the two companies successfully developed the first version of the new system, the partnership deteriorated due to mounting creative differences. From Microsoft's founding in 1975 until 2006, Gates had primary responsibility for the company's product strategy. He gained a reputation for being distant from others; as early as 1981 an industry executive complained in public that "Gates is notorious for not being reachable by phone and for not returning