This paper presents a versatile hardware/software cosimulation and co-design environment for embedded 3D graphics accelerators. The GRAphics AcceLerator design exploration framework (GRAAL) is an open system which offers a coherent development methodology based on an extensive library of SystemC RTL models of graphics pipeline components. GRAAL incorporates tools to assist in the visual debugging of the graphics algorithms implemented in hardware, and to estimate the performance in terms of throughput, power consumption, and area.