CD-i or Compact Disc Interactive is the name of an interactive multimedia CD player developed and marketed by Royal Philips Electronics N.V. CD-i also refers to the multimedia Compact Disc standard utilized by the CD-i console, also known as Green Book, which was co-developed by Philips and Sony in 1986 (not to be confused with MMCD, the pre-DVD format also co-developed by Philips and Sony). The first Philips CD-i player, released in 1991 and initially priced around USD $700, was capable of playing interactive CD-i discs, Audio CDs, CD+G (CD+Graphics), Karaoke CDs, and Video CDs (VCDs), though the latter required an optional "Digital Video Card" to provide MPEG-1 decoding.