RI-DOS

RI-DOS (an acronym for Radiantelligence Disk Operating System) is an operating system for x86-based personal computers mostly developed by Radiantelligence. Released on July 1989, it became one of the first commercially viable alternatives to MS-DOS. It was developed by Jack Nicholson, and his friend, Tony Wile.

Today, RI-DOS faded into obscurity due to the popularity of OpenRadiantOS, Radiantelligence's main operating system since the 1990s.

History
On April 4, 1988, Jack Nicholson (at the time the head of RadiantIntelligence) began to collaborate with Tony Wile, a friend and computer enthusiast, on a similar operating system that would become the basis for RadiantIntelligence DOS.