The SNES CD was a CD-ROM expansion module project for the Super Nintendo Entertainment System that was ultimately abandoned by Nintendo. During the time they pursued the project, Nintendo had formed brief alliances with Sony and Philips to develop it.
Sony intended to release a combined Super Nintendo with their CD-ROM as the original PlayStation; Nintendo's snubbing of Sony eventually led to the development of their own system that was called the PlayStation.
Philips was given license by Nintendo to develop games for their CD-i entertainment system (and possibly for the SNES CD) based on Mario and Legend of Zelda characters. These games are not considered canon and are widely considered the worst games in their respective franchises.