Acknowledgments.- Introduction, Dominique Guin, Kenneth Ruthven and Luc Trouche.- Calculators in mathematics education: a rapid evolution of tools, with differential effects, Luc Trouche.- A CAS as an assistant to reasoned instrumentation, Philippe Elbaz-Vincent.- Transposing computer tools from the mathematical sciences into teaching, Jean-Baptiste Lagrange.- The influence of a computer algebra environment on teachers' practice, Margaret Kendal, Kaye Stacey and Robyn Pierce.- Using symbolic calculators to study mathematics, Jean-Baptiste Lagrange.- An instrumental approach to mathematics learning in symbolic calculators environments, Luc Trouche.- Computer algebra as an instrument: examples of algebraic schemes, Paul Drijvers and Koeno Gravemeijer.- Instrumental genesis, individual and social aspects, Luc Trouche.- The integration of symbolic calculators into secondary education: some lessons from didactical engineering, Michèle Artigue.- Conclusion, Dominique Guin, Kenneth Ruthven and Luc Trouche.-Index.