  We investigate the integrable $(2+1)$-dimensional generalized dispersionless
KP (GdKP) equation (or Manakov-Santinit system) from the Lax-Sato form. Several
particular three-component reductions are considered so that the GdKP equation
can be reduced to hydrodynamic systems. Then one can construct infinite exact
solutions of GdKP by the generalized hodograph method.
