The MSX standard was designed by ASCII Corporation in cooperation with Microsoft. The latter provided a firmware version of its BASIC for the machine. Because this BASIC version was an extended version of MicroSoft Basic, it was called "MicroSoft eXtended BASIC", thus explaining the abbreviation MSX.
MSX computers proved to be popular in Asia (Korea, Japan), South America (Brazil, Chile), Europe (Netherlands, France, Spain, Finland) and the former Soviet Union. They were virtually unknown in the USA, however. The only MSX machines ever sold in the USA were an early SpectraVideo model and the Yamaha CX-5M, which while essentially an MSX, was marketed as a musical instrument rather than a home computer.