Darboux covariant 2+1 dimensional soliton equations of inhomogeneous type

We present 2+1 dimensional soliton equations of inhomogeneous tape which are derived systematically using the covariance with respect to the Darboux transformation. By setting Darboux invariants to be explicit functions of space-time, we obtain nonlinear equations describing soliton propagation in media with inhomogeneities. Darboux covariant equations obtained here include the inhomogeneously generalized Davey-Stewartson equation, the 2+1 dimensional modified Korteweg-de Vries equation and other binary Darboux covariant equations of inhomogeneous type.