Thanks. You may wish to look through lines 381-383ish on ac.scm, which is the bit which calls 'require when you're trying to (using ...) some package.
I think pack.arc is nice enough to integrate into ac.scm and arc.arc (at the very least the package loading part; you can probably still retain the bit that creates packages into pack.arc, since it'll probably be used rarely enough)
Also, it might make sense to use the same context object for each file in a pack.
