  We consider synchronization of chaotic systems coupled indirectly through a
common environmnet where the environment has an intrinsic dynmics of its own
modulated via feedback from the systems. We find that a rich vareity of
synchronization behavior, such as in-phase, anti-phase,complete and anti-
synchronization is possible. We present an approximate stability analysis for
the different synchronization behaviors. The transitions to different states of
synchronous behaviour are analyzed in the parameter plane of coupling strengths
by numerical studies for specific cases such as Rossler and Lorenz systems and
are characterized using various indices such as correlation, average phase
difference and Lyapunov exponents. The threshold condition obtained from
numerical analysis is found to agree with that from the stability analysis.
