  In this talk I briefly review the recent developments on light scalar meson
spectroscopy, paying particular attention to the causes of major revision of
the $\sigma$ or $f_0(500)$ meson in the Review of Particle Phsycis. This
resonance, despite playing a central role in the nucleon-nucleon attraction as
well as the QCD chiral symmetry breaking, has suffered a longstanding
controversy which has been acknowledged to be finally settled. The combination
of new and precise data together with rigorous dispersive approaches has turned
the old confusing situation about the properties of these mesons, and even thir
existence in some cases, into a field which now aims at precision studies.
