The generalized availability, and the abundance, of digital resources for mathematics teachers entail a complete metamorphosis of the curriculum material, still in progress. They also yield a deep change in teachers’ professional knowledge and development. This statement leads to study mathematics teachers’ documentation work: looking for resources, selecting/designing mathematical tasks, planning their succession, managing available artifacts, sharing recombined resources etc. This documentation work is at the core of teachers’ professional activity and professional development.
Building on previous and ongoing research projects (about secondary school mathematics), I will display an approach of individual and collective aspects of this documentation work, enlightening changes brought by digital resources.

References
Gueudet, G., Trouche, L. (online) Towards new documentation systems for mathematics teachers? Educational Studies in Mathematics.
Gueudet, G., Trouche, L. (2008) Collective documentational activity as a mode of teachers’ training : which methodological assistants ? ECER Conference, Göteborg.
Bueno-Ravel, L., Gueudet, G (2007) Online resources in mathematics: teachers’ genesis of use, in Pitta-Pantazi, D. and Philippou, G. Proceedings of the fifth congress of the European Society for Research in Mathematics Education, CERME 5, Larnaca, Chypre, http://ermeweb.free.fr/CERME5b/.