This paper describes the processes and challenges which led to the development of the D-Vision PostSUITE range of on-line, broadcast quality digital non-linear editing (NLE) systems, the first such professional system to take advantage of Windows NT technology. It starts by briefly discussing the history of non-linear editing as we know it, and charts the early development of disk-based, computer controlled editing systems. It then continues by looking at the challenges faced in the early 1990s by companies active in that field. Technologies were changing rapidly, making equipment obsolescent sooner. This, linked to increasing end-user demand for technology which would deliver higher quality, integrate seamlessly and be more reliable, at a fraction of the cost of contemporary systems led to the development of the latest generation of NLEs, and the advent of OpenDML and ActiveMovie.