France Directorate for Assessment, Forecasting and Performance (DEPP) – Office for Student Assessment
Luxembourg Department for the Coordination of Research in Pedagogical and Technological Innovation (SCRIPT)
Italy National Institute for the Educational Evaluation of Instruction and Training (Invalsi)
Portugal Institute for Educational Evaluation (IAVE)
Since then, Centro de Políticas Públicas e Avaliação da Educação da Universidade Federal de Juiz de Fora (CAEd/UFJF, Brazil) has joined the initiative.
OAT, home of TAO: https://www.taotesting.com/