This article is from the storage FAQ part2, by Rodney D. Van Meter with numerous contributions by others.
I'm not sure if ADIC manufactures or OEMs their robotics, but they apparently sell to end users. They have 8mm, 4mm and DLT autochangers in a variety of small to medium sizes, up to about a terabyte. See http://www.adic.com. (rdv,97/3/18)