EMV® is a trademark dating back to 1999, and it refers to all of the specifications administered by EMVCo. The original EMV Specification (for chip-based payment instruments) is now in v4.3, with backwards-compatible EMV Next Generation Specifications in development. (
http://www.emvco.com/about_emv.aspx)
EMV and EMVco are the same thing. It's the standard also implemented by RFID cards such as Mastercard PayPass and apps like Google Wallet.
