GRISLI has been developed by Ritz et al. (2001) at LGGE (CNRS, France). It is able to simulate both grounded and floating ice. The grounded part uses the Shallow Ice Approximation (SIA, Hutter, 1983) whereas ice shelves and ice streams are simulated following the Shallow Shelf Approximation (SSA, MacAyeal, 1989). The ice shelf formulation in GRISLI allows for a more realistic calculation of the ice sheet growth, and particularly of the advance of ice onto the shallow continental shelves in both hemispheres high latitudes. GRISLI has been validated over Antarctica, Greenland and successfully applied to study the inception of ice sheets during the last glacial cycle. At CMCC, GRISLI has been used to simulate the glacial inceptions of the last two glacial cycles and the penultimate glaciation in the framework of the climate service in contract with the Swedish Nuclear Fuel and Waste and Management Company. The following document provides a detailed description of the model and some indications to set up and run simulations.