Apple was created in the 1970s. It was first implemented on the Apple I computer, released in July 1976. Windows did not was only developed in 1982, but its predecessor MS-DOS was created in 1980. They were both startups founded by groups of classmates. Apple employee John Sculley left Microsoft in 1985, bringing information that allowed them to include features similar to Apple's programming. This made Windows one of Apple's biggest competitors. In 1997, an alliance was created between the two, Microsoft invested $150 million in Apple shares and Apple included Internet Explorer in its Mac operating system.