To celebrate the hundredth edition of the journal, the editors-in-chief (Raymond Bourdoncle, Anne-Marie Chartier, Françoise Lantheaume, Patrick Rayou, Anne Barrère, Cédric Frétigné and Stéphanie Rubi) have chosen to republish key contributions which they introduce. Each author was then invited to react to their initial text, to explain what issues were involved, what had remained the same and what needed to be revised.