It is no exaggeration to say that the advent of translation-memory (TM) systems in the translation profession has led to drastic changes in translators' processes and workfl ow, and yet, though many professional translators nowadays depend on some form of TM system, this has not been the object of much research. Our paper attempts to fi nd out what we know about the nature, applications and infl uences of TM technology, including translators' interaction with TMs, and also how we know it. An essential part of the analysis is based on a selection of empirical TM studies, which we assume to be representative of the research fi eld as a whole. Our analysis suggests that, while considerable knowledge is available about the technical side of TMs, more research is needed to understand how translators interact with TM technology and how TMs infl uence translators' cognitive translation processes.