Sliding Door Tech

I thought the following article was interesting:
http://www.designnews.com/contents/pdf/Groschopp-SlidingDoorChallenge.pdf

First, because it is a typical tech brief type article that you see in various technical theatre resources. But also because the topic of the challenge was something that is very theatrical. Alright, I know that most sets don't have automated glass sliding doors, but we do sometimes have elevator doors. And we have a variety of other things that need to slide in a small footprint very quietly.