Recent developments in practical quantum engineering and control techniques have allowed significant developments for experimental studies of open quantum systems and decoherence engineering. Indeed, it has become possible to test experimentally various theoretical, mathematical, and physical concepts related to non-Markovian quantum dynamics. This includes experimental characterization and quantification of non-Markovian memory effects and proof-ofprinciple demonstrations how to use them for certain quantum communication and information tasks. We describe here recent experimental advances for open system studies, focussing in particular to non-Markovian dynamics including the applications of memory effects, and discuss the possibilities for ultimate control of decoherence and open system dynamics.Introduction. -Closed quantum systems evolve by unitary dynamics conserving, e.g., the purity of the evolving quantum state. Thereby, having ability to prepare any initial pure quantum state for a given system, and having arbitrary time dependent and controllable Hamiltonian driving the system, allows to create any pure state trajectory in the system's Hilbert space -at least in principle. For an open quantum system interacting with its environment, the problematics of quantum control becomes more challenging. An open system, whose Hamiltonian we may be able to control to certain extent, interacts with a large number of uncontrollable degrees of freedom. The open system dynamics becomes non-unitary and the systemenvironment interaction tends, e.g., to reduce the purity of the open system state via decoherence, i.e., making it more mixed and classical-like. The question now becomes how can we control, not only how decoherence influences the open system dynamics, but also whether it is possible to control the loss of purity -and even increase the purity and revive the quantum properties at least temporarily?