25 years of seesaw (summary of SEESAW'25)

The seesaw mechanism for neutrino masses and its implications in particle physics and cosmology have been discussed actively over the last 25 years. The SEESAW'25 conference, which took place in Paris on 10-11 June 2004, just before the Neutrino 2004 conference, reviewed these 25 years of seesaw and discussed recent questions of interest. We summarize the different issues that were raised during the conference.