Microsoft was thrust onto the throne of technology and soon Gates and Allen became billionaires.
With his sister Jody Allen in 1986, he founded Vulcan, the investment firm that oversees his business and philanthropic efforts. He founded the Allen Institute for Brain Science and the aerospace firm Stratolaunch, which has built a colossal airplane designed to launch satellites into orbit. He has also backed research into nuclear-fusion power.
Allen later joined the list of America's wealthiest people who pledged to give away the bulk of their fortunes to charity. In 2010, he publicly pledged to give away the majority of his fortune, saying he believed "those fortunate to achieve great wealth should put it to work for the good of humanity."
Amongst many other things, he also bankrolled Scaled Composites suborbital flight program which achieved the first private suborbital spaceflight with SpaceShipOne.
