Unified model for dark energy

New models for the universe filled with generalized Chaplygin fluids are considered which unitarily describe as a single vacuum entity either both a quintessence scalar field and a cosmological constant, or dark matter and dark energy, so respectively unifying the notion of dark energy and that of all dark components. While the evolution of the universe filled with such fluids does not obviously contradict the present cosmic acceleration, the introduced single dark-energy and dark-matter components, for equations of state with characteristic parameter ω⩾−1, behaves like either an usual quintessence fluid with constant equation of state or pure dark matter, at early high densities, and, in any case, like a pure cosmological constant at late cosmological times.