README for github as dzil plugin
parallel forky each
doc @_ passing
type errors, lint, die
path utils demo & test
overlay dogfood for compose
combinatorial testing
state threading example
test memory sharing
$overlay = diff($old,$new)
GLOB, SCALAR, REF, blessed
recursive default?

Melb.pm: defor, Math::BigFloat & dumping, =namespace config,
    blessing the overlay objects (as a way to tag actions out of band)