Many forefront astrophysical studies are based on imaging survey data. There is a clear need to complement them with dedicated spectroscopic surveys, especially at medium and high resolution. While some 4-m class instruments exist or have been planned, a real gain can be obtained by transforming the CFHT in a 10-m telescope to perform wide-field, high- multiplexing, multi object spectroscopy by the end of 2020. This talk will report on the scientific and technical results from the current conceptual design study. Some innovative design solutions have been proposed to meet technical and programmatic requirements with existing technologies.