This paper presents a generalized Chaplygin gas model with an equation of state $ p = -A/\rho^{\alpha} $, where $ 0 < \alpha \leq 1 $. The model describes a universe evolving from a matter-dominated phase to a de Sitter phase via an intermediate phase with an effective equation of state $ p = \alpha \rho $. The model is shown to interpolate between a dust-dominated phase and a de Sitter phase, and can be interpreted as a generalized Nambu-Goto action in a (d+1,1) spacetime. The model is also shown to unify dark matter and dark energy, and to be compatible with standard structure formation scenarios without leaving undesirable signatures on the Cosmic Microwave Background power spectrum. The model is analyzed in the context of inhomogeneous cosmology, and it is shown that the density contrast in the Chaplygin gas model closely resembles that of the standard CDM model for any value of $ \alpha \neq 0 $. The model is also shown to yield a density contrast that decays for large a, similar to the $ \Lambda $ CDM model. The paper concludes that the Chaplygin gas model, and its generalizations, contain some of the key ingredients in the description of the Universe dynamics at early and late times.This paper presents a generalized Chaplygin gas model with an equation of state $ p = -A/\rho^{\alpha} $, where $ 0 < \alpha \leq 1 $. The model describes a universe evolving from a matter-dominated phase to a de Sitter phase via an intermediate phase with an effective equation of state $ p = \alpha \rho $. The model is shown to interpolate between a dust-dominated phase and a de Sitter phase, and can be interpreted as a generalized Nambu-Goto action in a (d+1,1) spacetime. The model is also shown to unify dark matter and dark energy, and to be compatible with standard structure formation scenarios without leaving undesirable signatures on the Cosmic Microwave Background power spectrum. The model is analyzed in the context of inhomogeneous cosmology, and it is shown that the density contrast in the Chaplygin gas model closely resembles that of the standard CDM model for any value of $ \alpha \neq 0 $. The model is also shown to yield a density contrast that decays for large a, similar to the $ \Lambda $ CDM model. The paper concludes that the Chaplygin gas model, and its generalizations, contain some of the key ingredients in the description of the Universe dynamics at early and late times.