EVE is a polarization lidar system that emits light of multiple polarization states, implementing a dual-laser/dual-telescope configuration. The system has been developed by the Greek company Raymetrics S.A., with the support of the ReACT team and the Ludwig Maximilians University in Munich. EVE lidar will provide Aeolus, an ESA satellite mission, with ground reference measurements for the validation and assessment of the aerosol and clouds related products.