This article is from the storage FAQ part2, by Rodney D. Van Meter with numerous contributions by others.
HIARC HSM runs on Solaris 2.4 and above. Slides in at the vnode layer. Supports 4mm, 8mm, 3480, DLT, VHS, D-1 and D-2 tape drives, and appropriate robotics (I don't have a specific list). Removable media formats are standard (_which_ standard, I don't know). Pricing from $4k to $25k is reasonable for the functionality. See http://www.hiarc.com. (rdv, 97/3/20)