Once a programmer who co-wrote the original Altair BASIC interpreter, Gates built Microsoft into one of the world's fastest growing and most successful software companies. There is some controversy about Gates' role in the building of the company. Early accounts show that Microsoft, under Gates' control, negotiated contracts with IBM poorly and accepted a licensing model rather than an outright sale only as IBM refused to buy the operating system Gates held rights to. It seems that luck played an important role in the early years of Bill Gates' control of Microsoft.
Altair BASIC later became Microsoft BASIC, and ended up on IBM PCs.
Bill Gates also has founded along with his wife Melinda the Gates Foundation, a charitable organization.