  We review the main ideas underlying the emerging theory of Yangians -- the
new type of hidden symmetry in string-inspired models. Their classification by
quivers is a far-going generalization of simple Lie algebras classification by
Dynkin diagrams. However, this is still a kind of project, while a more
constructive approach goes through toric Calabi-Yau spaces, related
supersymmetric systems and the Duistermaat-Heckmann/equivariant integrals
between the fixed points in the ADHM-like moduli spaces. These fixed points are
classified by crystals (Young-type diagrams) and Yangian generators describe
``instanton'' transitions between them. Detailed examples will be presented
elsewhere.
