The MSX standard has been designed by a company called ASCII in cooperation with Microsoft which provided a firmware version of its BASIC for the machine. There is a widespread rumor that "MSX" stands for "MicroSoft eXtended". The MSX machines were produced by such giants as Sony, Yamaha, Panasonic, Toshiba, Daewoo, and Philips. The only MSX model ever sold in USA appears to be an early SpectraVideo machine.
In spite of its sad history, MSX is a very nice computer, especially useful for educational purposes which is clearly indicated by example of the Soviet Union. Russian Ministry of Education bought hundreds of MSXes (and later MSX2s) grouped into "computerized classroom systems" of 10-16 machines connected into a simple network. Entire generation of programmers has grown up using these computers.
Hardware-wise, MSX represents a hybride of a videogame console and a generic CP/M-80 machine. Its heart is a Z80 CPU working at 3.58MHz in the base model. The clock frequency has been doubled in the TurboR. The video subsystem is built around a TI9918 or TI9928 VDP chip also used in Texas Instruments' TI-99/4 computers, ColecoVision, and Coleco Adam. In the later MSX models this chip has been upgraded to V9938 (MSX2) and V9958 (MSX2+ and TurboR). The latest version of it is V9990. The audio system is handled by AY-3-8910 chip by General Instruments, same as the one used in Sinclair ZXSpectrum128 audio. AY-3-8910 provides 3 channels of synthetized sound, noise generation, and two general purpose parallel IO ports which are used for joysticks and some other things in the MSX design. Due to their hardware structure, MSX machines were perfectly suitable for games and there is a lot of good games either written or ported to them.