On the "getting started" page, there is a heading called "Register Machines". The first thing I thought of was http://en.wikipedia.org/wiki/Register_machine . Given your audience, that choice of words might be confusing :)
I think there's a point where we have to accept that the English language is heavily overloaded, and trust that our readers will be able to understand our meaning from the context. :-)
But speaking of theoretical CS concepts: Part of the tarsnap source code implements a "multitape layer" -- which, in this case, refers to code which uses block storage to provide multiple simulated tapes -- but I spent a long time trying to think of a different name for it in order to avoid any confusion with multitape Turing machines.
