  Over the last two decades, significant advances have been made in the design
and analysis of fixed-parameter algorithms for a wide variety of
graph-theoretic problems. This has resulted in an algorithmic toolbox that is
by now well-established. However, these theoretical algorithmic ideas have
received very little attention from the practical perspective. We survey recent
trends in data reduction engineering results for selected problems. Moreover,
we describe concrete techniques that may be useful for future implementations
in the area and give open problems and research questions.
