  We present a collection of well-conditioned integral equation methods for the
solution of electrostatic, acoustic or electromagnetic scattering problems
involving anisotropic, inhomogeneous media. In the electromagnetic case, our
approach involves a minor modification of a classical formulation. In the
electrostatic or acoustic setting, we introduce a new vector partial
differential equation, from which the desired solution is easily obtained. It
is the vector equation for which we derive a well-conditioned integral
equation. In addition to providing a unified framework for these solvers, we
illustrate their performance using iterative solution methods coupled with the
FFT-based technique of [1] to discretize and apply the relevant integral
operators.
