Ghislaine Gueudet is professor in mathematics didactics. She works at the University of Western Brittany in France. She is co-director of the CREAD (Center for Research on Education, Learning and Didactics). Her research concerns the interactions between teachers and resources (with a specific focus on online resources), and their consequences in terms of professional development. This theme lead her to develop, together with Luc Trouche, a documentational approach to didactics. Web page: http://cread.bretagne.iufm.fr/spip.php?article447 Birgit Pepin is professor of mathematics didactics at Sør-Trøndelag University College in Trondheim, Norway. For many years she has worked with mathematics teachers in terms of professional development, and in different countries. One of her main research projects concerns teachers working with mathematics curriculum materials, including textbooks, in order to develop knowledge in/for teaching. webpage: http://hist.no/content/35372/Pepin-Birgit Luc Trouche is professor in mathematics didactics. He is director of research in the IFE (French Institute of Education), located in the ENSL (Ecole Normale Supérieure de Lyon). His research concerns the conceptualisation of mathematics in digital environments, and, more recently, with Ghislaine Gueudet, the professional development of mathematics teachers working on/with resources. Webpage: http://educmath.inrp.fr/Educmath/recherche/educmath/page_luc_trouche/