track mounted lights

[timwatson19]

At the PLASA show last year, I noticed a stand where they were demonstrating a track mounting system for moving lights. This consisted of a truss-mounted track, similar to curtain track except for a series of busbars to take power/data to the light. On this track was mounted a motorised carriage, coupled to an unmotorised carriage, to which a light was mounted. The carriage was DMX controlled, and could move forwards or backwards along the track at variable speed. Could anybody tell me who makes this system, as I am interested in finding out more about it.