Whilst some of us collect famous brands, or bikes with pedigree, and others like myself any old rubbish which catches their fancy, there was a period when the mainstream bicycle collectors were obsessed with "system" devices and bikes. System, for want of a better definition which somebody else may be able to supply, is the ones that didn't make it to the market. Or not fo r very long. One could also safely say that most "system" is stuff that gre w randomly on the bicycle evolution tree, but didn't ramify. It just died. Some of it was utalitarian, some of it racing.
Got a nice example of a "system" bar/brake combo here http://tiny.cc/
Nick March, Agen, 47000 Lot et Garonne, France